The Federal Food, Drug, and Cosmetic Act authorizes the Food and Drug Administration(FDA) to regulate products as "drugs" or "devices" whenthey are "intended to affect the structure or any function of the body."21 U.S.C. 321(g)(1)(C) and (h)(3). FDA has found that the nicotine in tobaccoproducts is intended by tobacco manufacturers to cause and sustain a user'saddiction to nicotine and to act as a sedative, stimulant, and appetitesuppressant. The question presented is whether, given that finding, tobaccoproducts are subject to regulation under the Act as "drugs" and"devices."


PARTIES TO THE PROCEEDING
The petitioners are: Food and Drug Administration, and Jane E. Henney, Commissionerof Food and Drugs.
The respondents are: Brown and Williamson Tobacco Corp.; Lorillard TobaccoCompany; Philip Morris, Incorporated; RJ Reynolds Tobacco Company; CoyneBeahm, Incorporated; National Association of Convenience Stores; ACME Retail,Incorporated; United States Tobacco Company; Conwood Company, LP; NationalTobacco Company, LP; Pinkerton Tobacco Company; Swisher International, Incorporated;Central Carolina Grocers, Incorporated; J.T. Davenport, Incorporated; NorthCarolina Tobacco Distributors Committee, Incorporated; The American AdvertisingFederation; American Association of Advertising Agencies; Association ofNational Advertisers, Incorporated; Magazine Publishers of America; theOutdoor Advertising Association of America, Incorporated; and Point of PurchaseAdvertising Institute.



In the Supreme Court of the United States


No. 98-1152

FOOD AND DRUG ADMINISTRATION, ET AL., PETITIONERS

v.

BROWN AND WILLIAMSON TOBACCO CORP., ET AL.


ON WRIT OF CERTIORARI
TO THE UNITED STATES COURT OF APPEALS
FOR THE FOURTH CIRCUIT



BRIEF FOR THE PETITIONERS


OPINIONS BELOW

The opinion of the court of appeals (Pet. App. 1a-75a) is reported at 153F.3d 155. The opinion of the district court (Pet. App. 76a-136a) is reportedat 966 F. Supp. 1374. The Food and Drug Administration's jurisdictionaldetermination and final rule concerning tobacco products are published at61 Fed. Reg. 44,396 (1996), and 61 Fed. Reg. 44,619 (1996).1

The judgment of the court of appeals was entered on August 14, 1998. A petitionfor rehearing was denied on November 10, 1998. Pet. App. 137a-146a. Thepetition for a writ of certiorari was filed on January 19, 1999, and wasgranted on April 26, 1999. The jurisdiction of this Court rests on 28 U.S.C.1254(1).
STATUTORY AND REGULATORY PROVISIONS INVOLVED
The relevant provisions of the Federal Food, Drug, and Cosmetic Act appearin an appendix to this brief. The tobacco product regulations appear inthe appendix to the petition for a writ of certiorari.

1. The Federal Food, Drug, and Cosmetic Act (Act), ch. 675, 52 Stat. 1040,21 U.S.C. 301 et seq., confers authority on the Secretary of Health andHuman Services, through the Food and Drug Administration (FDA), to regulate"drugs" and "devices" for the purpose of protectingthe public health. See 21 U.S.C. 393(b)(1), (2)(B) and (C). The Act defines"drug" as, inter alia, "articles (other than food) intendedto affect the structure or any function of the body of man or other animal."21 U.S.C. 321(g)(1). The Act similarly defines "device" as, interalia, "an instrument, apparatus, * * * contrivance, * * * or othersimilar or related article, including any component, part, or accessory,* * * intended to affect the structure or any function of the body of manor other animals, and which does not achieve its primary intended purposesthrough chemical action within or on the body * * * and which is not dependentupon being metabolized for the achievement of its primary intended purposes."21 U.S.C. 321(h)(3).
The Act recognizes that certain products may constitute a combination ofa drug and a device. 21 U.S.C. 353(g)(1). FDA may regulate drug/device combinationproducts by using its authority to regulate drugs, its authority to regulatedevices, or both. 61 Fed. Reg. 44,400-44,403 (1996). One provision relatingto devices authorizes FDA, by regulation, to "require that a devicebe restricted to sale, distribution, or use * * * upon such * * * conditionsas [FDA] may prescribe in such regulation, if, because of its potentialityfor harmful effect or the collateral measures necessary to its use, [FDA]determines that there cannot otherwise be reasonable assurance of its safetyand effectiveness." 21 U.S.C. 360j(e)(1).

2. In response to petitions requesting that FDA regulate tobacco products,FDA conducted an extensive investigation, issued a proposed rule and "jurisdictional"analysis, and invited public comment. 60 Fed. Reg. 41,314 (1995). In August1996, FDA determined that tobacco products constitute a combination of a"drug" and a "device" and issued regulations directedto those products. 61 Fed. Reg. at 44,396; id. at 44,619.
FDA based its determination that tobacco products are "drugs"and "devices" on two key findings: (a) extensive scientific documentationestablishes that the nicotine in tobacco products "affects the structureor any function of the body" because it causes and sustains addiction,and acts as a sedative, stimulant, and appetite suppressant, 61 Fed. Reg.at 44,630, 44,664-44,685; and (b) those effects are "intended"by the manufacturers of tobacco products. Id. at 44,630, 44,686-45,204.
a. In finding that the nicotine in tobacco products affects the structureand function of the body, FDA relied on scientific evidence that nicotinedirectly affects a part of the brain known as the mesolimbic system, whichrewards the repeated consumption of certain pleasurable substances. By increasingthe activity of dopamine within that system, nicotine causes the compulsivedrug-seeking behavior of drug addiction. 61 Fed. Reg. at 44,700, 44,721.In some circumstances, and in some doses, nicotine in tobacco products actsas a sedative, while in other circumstances and doses, it acts as a stimulant.Id. at 44,666. Studies also show that nicotine can cause weight loss. Ibid.FDA found that those effects on the structure and function of the body arequintessentially drug-like, identical to those FDA has found in numerousother products that it regulates under the Act, including stimulants, tranquilizers,appetite suppressants, nicotine replacement products, and narcotics usedto treat addiction. Id. at 44,632, 44,666-44,670.
b. In finding that the effects of tobacco products on the structure andfunction of the body are "intended," FDA drew on three categoriesof evidence.
First, FDA found that nicotine's widely recognized addictive propertiesmake it foreseeable to any reasonable manufacturer that a substantial proportionof users of tobacco products will consume them to satisfy their addiction.61 Fed. Reg. at 44,701-44,739. FDA also found that nicotine's mood-alteringeffects and its effects on weight are so well established that a reasonablemanufacturer would foresee that tobacco products would be used by a substantialproportion of consumers for those purposes as well. Id. at 44,634-44,635,44,698-44,701, 44,739-44,744. Those findings, FDA determined, are sufficientin themselves to meet the statutory standard of "intended" effects,because "[i]t is a widely accepted legal principle that persons canbe held to 'intend' the reasonably foreseeable consequences of their actions."Id. at 44,691 (citing, inter alia, Agnew v. United States, 165 U.S. 36,53 (1897) ("The law presumes that every man intends the legitimateconsequence[s] of his own acts.")).
Second, FDA found that consumers do in fact use tobacco products predominantlyfor pharmacological purposes. 61 Fed. Reg. at 44,635-44,636, 44,807-44,846.As many as 92% of all cigarette smokers and 75% of all young persons whoregularly use smokeless tobacco consume those products because they areaddicted to the nicotine in them. Id. at 44,635-44,636. Indeed, the percentageof smokers addicted to nicotine is higher than the percentage of heroinand cocaine users addicted to those drugs. Id. at 44,812-44,813. More than70% of young daily smokers and 50% of young daily smokeless tobacco usersconsume tobacco products to obtain their mood-altering effects. Id. at 44,636.As many as one-half of young persons who smoke do so to control their weight.Ibid. Although some people also use tobacco products for their taste orbecause they like the ritual, those purposes are clearly secondary. Id.at 44,807, 44,826-44,827. FDA determined that, "[w]here consumers usea product predominantly or nearly exclusively to obtain any of the effectson the structure or function of the body produced by a substance, such evidencewould alone be sufficient to establish manufacturer intent." Id. at44,807 (citing Action on Smoking & Health v. Harris, 655 F.2d 236, 239-240(D.C. Cir. 1980)).
Third, FDA relied on statements, research, and actions of the manufacturersthemselves, which showed that the manufacturers intend their products toaffect the structure and function of the body. 61 Fed. Reg. at 44,847-45,097.That extensive evidence, FDA concluded, satisfies the standard dictionarydefinitions of "intend," because it shows that manufacturers "havein mind" the pharmacological effects and uses of their tobacco productsand "design" them to enhance those effects and uses. Id. at 44,851& n.413 (quoting, inter alia, The American Heritage Dictionary of theEnglish Language 668 (2d ed. 1991)).
FDA cited recently discovered evidence that the leading tobacco manufacturershave long known that consumers use tobacco products to obtain the pharmacologicaleffects of nicotine. 61 Fed. Reg. at 44,636-44,640, 44,854-44,915. For example,as early as 1969, the vice president for research and development for PhilipMorris informed the board of directors that "the ultimate explanationfor the perpetuated cigaret habit resides in the pharmacological effectof smoke upon the body of the smoker." Id. at 44,855. In the ensuingdecades, Philip Morris researchers described a cigarette as "a dispenserfor a dose unit of nicotine," id. at 44,856, observed that cigarettesserve as "a narcotic, tranquilizer, or sedative," id. at 44,857,characterized nicotine as "a powerful pharmacological agent with multiplesites of action," ibid., and reported that "it is well recognizedwithin the cigarette industry that there is one principal reason why peoplesmoke -to experience the effects of nicotine, a known pharmacologicallyactive constituent in tobacco," id. at 44,858.
Similarly, a memorandum from the early 1970s shows that R.J. Reynolds (RJR)scientists regarded nicotine as a "potent" and "habit-forming"drug, considered cigarettes to be "a vehicle for delivery of nicotine,"and conceived of the tobacco industry itself as "a specialized, highlyritualized and stylized segment of the pharmaceutical industry." 61Fed. Reg. at 44,867. The memorandum also stated that "the confirmeduser of tobacco products is primarily seeking the physiological 'satisfaction'derived from nicotine," and that "what we are really selling [is]nicotine satisfaction." Id. at 44,868. RJR researchers later reiteratedthat "[w]ithout any question, the desire to smoke is based on the effectof nicotine on the body," that "a confirmed smoker attempts toget a certain desired level of nicotine," and that "[t]he nicotinein the blood acts upon the central nervous system and produces in the averagesmoker a sensation one could describe as either stimulating or relaxing."Id. at 44,871.
In the 1960s, a senior advisor to the board of British American TobaccoCompany (BATCO), the parent company of Brown & Williamson, stated that"smoking is a habit of addiction," and that "nicotine isa very remarkable beneficent drug that both helps the body to resist externalstress and also can as a result show a pronounced tranquillising effect."61 Fed. Reg. at 44,882. During the same period, Brown & Williamson'sgeneral counsel stated that "nicotine is addictive" and that "[w]eare, then, in the business of selling nicotine, an addictive drug."Id. at 44,884. BATCO researchers also stated that "puffing behaviouris the means of providing nicotine dose in a metered fashion." Id.at 44,890.
FDA further found that cigarette manufacturers acted on the basis of theirstatements and research concerning the pharmacological effects of tobaccoproducts. In particular, FDA found that "[m]anufacturers of commerciallymarketed cigarettes commonly manipulate nicotine deliveries to provide remarkablyprecise, pharmacologically active doses of nicotine to consumers."61 Fed. Reg. at 44,951. Such manipulation is especially evident in low-tarcigarettes, which make up 80% of the cigarette market. Id. at 44,951-44,952.As tar levels are reduced, nicotine levels naturally fall. Id. at 44,976.To counteract that effect and to provide an active dose of nicotine in low-tarcigarettes, manufacturers use tobacco blends with higher nicotine content,id. at 44,954-44,957, ventilation systems that remove more tar than nicotinefrom smoke, id. at 44,963-44,967, and chemical additives that increase theamount of pharmacologically active nicotine in the smoke, id. at 44,970-44,971.
FDA likewise found evidence that manufacturers of smokeless tobacco manipulatenicotine deliveries. They market "starter" brands that have alow level of nicotine, so that new users may develop a tolerance for nicotinewithout experiencing nausea or vomiting. 61 Fed. Reg. at 44,643. They alsomarket regular brands to experienced users that are engineered to deliverthe level of nicotine necessary to sustain addiction. Ibid. Through marketingand advertising, manufacturers encourage those who have developed a tolerancefor starter brands to graduate to regular brands. Id. at 45,120.2
Finally, although FDA concluded that each of the three categories of evidencejust discussed independently supports its determination that manufacturersintend the pharmacological effects and uses of their tobacco products, thecumulative effect and convergence of the evidence "convincingly establishesthat cigarettes and smokeless tobacco are 'intended' to affect the structureand function of the body within the meaning of the Act." 61 Fed. Reg.at 45,203-45,204.
c. Having concluded that tobacco products fall squarely within the "drug"and "device" definitions, FDA next examined the structure of theAct as a whole, prior agency statements concerning its authority to regulatetobacco products, Congress's failure to pass legislation that would haveexpressly authorized FDA to regulate tobacco products, and Congress's enactmentof certain tobacco-specific statutes. After carefully evaluating each ofthose considerations, FDA concluded that none of them detracts from theconclusion that tobacco products are "drugs" and "devices"under the Act. See, e.g., 61 Fed. Reg. at 44,412-44,413 (structure of theAct); id. at 45,219-45,252 (prior statements); id. at 45,255-45,259 (unenactedlegislation); id. at 44,544-44,548, 45,261-45,265 (tobacco-specific statutes).
d. In sum, FDA concluded that the nicotine in tobacco products is a "drug,"61 Fed. Reg. at 45,207, that tobacco products contain "device components"for the delivery of that drug, and that cigarettes and smokeless tobaccotherefore are "combination products" under the Act. Id. at 45,208-45,216.

3. a. FDA next determined that tobacco use is the largest cause of preventabledeath in the United States. 61 Fed. Reg. at 44,398. Tobacco kills more Americansannually than AIDS, car accidents, alcohol, homicides, illegal drugs, suicides,and fires combined. Ibid. FDA also found that tobacco use is a "pediatricdisease," id. at 44,421, because most people who use tobacco as adultsbegan smoking regularly during childhood. If adolescents can be kept tobacco-free,most will never start using tobacco as adults. Id. at 44,399. Efforts toprevent childhood tobacco use, however, have not been successful thus far.Approximately one million children begin to smoke every year. Id. at 44,568.One of every three young people who become regular smokers will die prematurelyfrom a tobacco-related disease. Id. at 44,399.
b. Because most tobacco-related addiction begins in childhood, FDA issuedregulations aimed at reducing the use of tobacco products by young people.It adopted access restrictions that, inter alia: (1) prohibit the sale oftobacco products to persons under age 18; (2) require retailers to checkthe identification of persons under age 27; and (3) prohibit vending machinesales and self-service displays of tobacco products except in adult-onlylocations. 61 Fed. Reg. at 44,616-44,617. FDA also issued regulations requiringtobacco product labeling to bear the established name of the product (e.g.,"cigarettes") and the statement, "Nicotine-Delivery Devicefor Persons 18 or Older." Id. at 44,617.
Based on evidence that "advertising plays a material role in the decisionof children * * * to engage in tobacco use," 61 Fed. Reg. at 44,489,and internal company documents showing the industry's concerted efforts"to attract young smokers" and "presmokers" throughadvertising, id. at 44,480, FDA concluded that restrictions on the formsof advertising that are most effective in attracting young smokers are necessaryto complement the access restrictions. Id. at 44,406-44,407. FDA's advertisingand promotion restrictions include: (1) a requirement that advertisementsappear in black-and-white, text-only format, except in adult publicationsand adult-only facilities; (2) a ban on outdoor advertising within 1000feet of schools and public playgrounds; (3) a prohibition on the sale ordistribution of hats, t-shirts, and other similar promotional products thatbear a tobacco product brand name or logo; and (4) a prohibition on sponsorshipof athletic, cultural, or other events in a tobacco brand name. Id. at 44,617-44,618.In adopting its access, labeling, and advertising restrictions, FDA invokedits authority under 21 U.S.C. 360j(e)(1) to place conditions on the sale,distribution, and use of a device if FDA determines that "there cannototherwise be reasonable assurance of its safety and effectiveness."

4. Respondents (tobacco companies, advertisers, and retailers) brought suitin the United States District Court for the Middle District of North Carolina,challenging the validity of FDA's tobacco product regulations. Respondentsmoved for summary judgment, arguing that: (1) FDA lacks statutory authorityto regulate tobacco products that are marketed without claims of therapeuticvalue; (2) FDA lacks statutory authority to regulate advertising of tobaccoproducts; and (3) FDA's advertising restrictions violate the First Amendment.For purposes of their summary judgment motion, respondents accepted as truethe facts found by FDA concerning the effects of tobacco products on thehuman body, and the intent of the manufacturers to cause those effects.Pet. App. 77a-78a n.1.
The district court granted in part and denied in part respondents' motionfor summary judgment. Pet. App. 76a-134a. The district court first heldthat FDA had lawfully concluded that tobacco products are subject to regulationas "drugs" and "devices." Id. at 80a-126a. The courtreasoned that, given FDA's finding that tobacco products are intended tocause and sustain addiction and to act as a stimulant, sedative, and weightregulator, tobacco products fit squarely within the Act's definitions of"drug" and "device." Id. at 81a, 104a-116a. The courtconcluded that FDA's previous statements concerning its authority to regulatetobacco products, Congress's failure to enact bills that would have expresslyauthorized FDA to regulate tobacco products, and the tobacco-specific statutesenacted after 1938 do not detract from the reasonableness of FDA's conclusionthat tobacco products are drugs and devices under the Act. Id. at 84a-101a.
The district court upheld FDA's restrictions on minors' access to tobaccoproducts as a valid exercise of FDA's authority under 21 U.S.C. 360j(e)(1)to impose conditions on the "sale, distribution, or use" of "devices."Pet. App. 133a. It also upheld FDA's labeling requirements. Id. at 134a.The court concluded, however, that FDA's advertising and promotion restrictionsare not authorized by Section 360j(e). Id. at 127a-133a. The district courtcertified all of its rulings for interlocutory appeal, id. at 135a, andthe court of appeals accepted that certification, id. at 11a.

5. a. In a 2-1 decision, a panel of the Fourth Circuit reversed, Pet. App.1a-75a, holding that "FDA lacks jurisdiction to regulate tobacco products,"and that "all of the FDA's August 28, 1996 regulations * * * are thusinvalid," id. at 11a-12a. The majority acknowledged that the plainmeaning of the drug and device provisions "may appear to support thegovernment's position that tobacco products fit within the Act's definitionsof drugs or devices." Id. at 19a. The majority determined, however,that FDA could not rely on the definitional provisions, because, in itsview, tobacco products do not fit into the Act's overall regulatory scheme.Id. at 20a-30a.
The majority concluded that, under 21 U.S.C. 360j(e), FDA has a responsibilityto determine that there is a reasonable assurance of safety of a productthat it declines to ban completely from the market. Pet. App. 21a-22a. BecauseFDA found tobacco products to be dangerous, the majority concluded, FDA'sfailure to prohibit the sale of such products does not "comply withthe terms of the very statutory provision it has chosen as its basis forregulation." Id. at 23a. The majority further concluded that, givenFDA's finding that tobacco products are not safe, several other provisionsof the Act would require FDA to ban the sale of tobacco products, a resultthe majority found to be in conflict with what it perceived to be Congress'sintent. Id. at 23a-30a. The majority concluded that "FDA's need tomaneuver around the obstacles created by the operative provisions of theAct reflects congressional intent not to include tobacco products withinthe scope of the FDA's authority." Id. at 29a-30a. The majority alsoconcluded that FDA's previous statements concerning the circumstances inwhich it would regulate tobacco products, Congress's failure to enact billsthat would have expressly authorized FDA to regulate tobacco products, andthe tobacco-specific statutes enacted since 1938 all corroborate that Congressdid not intend the original grant of authority to FDA to include regulationof tobacco products. Id. at 31a-52a.
b. Judge Hall dissented. Pet. App. 55a-75a. Observing that the "recordcontains voluminous evidence of the pharmacological effects of nicotine,"id. at 57a, and that such effects are "intended" by tobacco manufacturers,id. at 57a-59a, he concluded that "[t]obacco products fit comfortablyinto the [Act's] definitions of 'drug' and 'device,'" id. at 55a. JudgeHall rejected the majority's view that FDA's failure to prohibit the saleof tobacco products, despite finding them to be dangerous, demonstratesthat tobacco products are not covered by the Act. Id. at 60a-61a. He reasonedthat "[h]ow the FDA has chosen to regulate tobacco has no bearing onthe question of whether the agency has the authority to regulate it at all."Ibid. Judge Hall similarly disagreed with the majority's reliance on FDA'sprior decisions and statements regarding its authority to regulate tobaccoproducts. Id. at 63a-65a. He pointed out that "an agency can changeits view of what action is possible or necessary, particularly when newfacts come to light." Id. at 64a. Here, he explained, FDA had a strongbasis for changing its position because of new evidence that "nicotineis extremely addictive and that a large majority of tobacco users use theproduct to satisfy that addiction," and, even more important, becauseof new evidence that "manufacturers design their products to sustainsuch addiction." Id. at 65a. Judge Hall also disagreed with the majority'sreliance on unenacted bills, concluding that any inference that could bedrawn from that experience was offset by Congress's inaction following FDA'sannouncement of its proposed rule to regulate tobacco products. Id. at 61an.1. Finally, Judge Hall concluded that the "tobacco-specific"statutes cited by the majority address narrow subjects and fall far shortof showing that Congress intended to prevent FDA from exercising regulatoryauthority over tobacco products. Id. at 65a-70a.

The Food and Drug Administration reasonably concluded that tobacco productsare drugs and devices subject to regulation under the Act. Under ChevronU.S.A. Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984),FDA's conclusion is entitled to controlling weight.
A. The Federal Food, Drug, and Cosmetic Act defines "drug" and"device" to include products "intended to affect the structureor any function of the body," 21 U.S.C. 321(g)(1)(C) and (h)(3), andit does not exempt tobacco products from those definitions. Given FDA'sfinding that the nicotine in tobacco products is intended by manufacturersto sustain addiction and to act as a sedative, stimulant, and appetite suppressant,tobacco products plainly qualify as drugs and devices under the Act.
B. Tobacco products also have the classic characteristics of drugs and devicessubject to regulation under the Act: They are taken within the human body,they deliver a pharmacologically active substance to the bloodstream, andthey have potentially dangerous effects. Moreover, the intended pharmacologicaleffects of tobacco products mirror those of numerous other products thatFDA regulates, including tranquilizers, stimulants, weight-loss products,nicotine replacement products, and narcotics used to treat addiction.
Respondents' argument that tobacco products cannot be drugs or devices unlessthey are accompanied by express claims of therapeutic value is without merit.The text of the Act makes "intended" effects, not "marketclaims," the decisive factor. When, as here, consumers use a productpredominantly for its pharmacological effects, manufacturers know that iswhy consumers use their products, and manufacturers manipulate the contentof the product in order to promote those uses, an intent to affect the structureor function of the body is clearly established. FDA has regulated otherproducts intended to affect the structure or function of the body, despitethe absence of explicit market claims, and there is no principled basisfor treating tobacco products differently.
C. The court of appeals' view that tobacco products cannot be drugs or devices,because if they were, they would have to be banned, is incorrect. The Actauthorizes FDA to permit the continued marketing of drugs and devices, subjectto regulation, when it finds that the dangers of banning the product outweighthe benefits. FDA reasonably determined that, with respect to adults, thedangers of banning tobacco from the market outweigh the benefits, becausea ban would leave many users with untreatable symptoms of withdrawal, andwould predictably lead to the use of more dangerous black market products.If the Court were to overturn FDA's judgment concerning the risks and benefitsof leaving tobacco products on the market, however, that would simply meanthat the Act, as presently written, requires tobacco products to be banned.That consequence would in no way undermine FDA's conclusion that tobaccoproducts are intended to affect the structure or function of the body andare therefore drugs and devices subject to regulation under the Act.
D. Until FDA issued the regulations at issue here, the only instances inwhich it had found that tobacco products were intended to affect the structureor function of the body involved cases in which there were express marketclaims of therapeutic value. An agency is always free to change its positionon an issue, however, as long as it provides a reasoned explanation justifyingthe change, and FDA provided such a reasoned explanation here. FDA's conclusionthat tobacco products are intended to affect the structure or function ofthe body, regardless of whether manufacturers make express claims of therapeuticvalue, is based on overwhelming new evidence that nicotine is addictive,that consumers use tobacco products primarily to satisfy addiction and forits mood-altering effects, that manufacturers know that consumers use theirproducts primarily for those purposes, and that manufacturers have engineeredtheir products to deliver pharmacologically active doses of nicotine.
Nor is it significant that Congress has failed to enact bills that wouldhave expressly authorized FDA to regulate tobacco products. The Constitutionrequires Congress to express its will through enacted legislation, not unenactedbills. Congress's failure to enact bills that would have expressly authorizedFDA to regulate tobacco products therefore has no more bearing on the questionpresented in this case than does Congress's failure to enact other billsthat would have excluded tobacco products from the reach of the Act.
Finally, the tobacco-specific statutes enacted long after 1938 do not affectthe question presented here. Those statutes address narrow issues, suchas what warning labels should be placed on cigarette packages. None of thosestatutes exempts tobacco products from the reach of the Federal Food, Drug,and Cosmetic Act, and none of them remotely implies that FDA altogetherlacks authority to regulate tobacco products.

THE FOOD AND DRUG ADMINISTRATION VALIDLY DETERMINED THAT TOBACCO PRODUCTSARE "DRUGS" AND "DEVICES" WITHIN THE MEANING OF THEACT
After the most extensive rulemaking hearing in its history, the Food andDrug Administration determined that the nicotine in tobacco products isintended by tobacco manufacturers to cause and sustain addiction and toact as a stimulant, sedative, and appetite suppressant. The sole questionpresented in this case is whether, given that finding, FDA validly determinedthat tobacco products are subject to regulation as "drugs" and"devices" under the Act.
Because Congress has conferred on FDA the authority to administer the Act,21 U.S.C. 393(d)(2) (1994 & Supp. III 1997), and to issue regulationsto carry out its purposes, 21 U.S.C. 371(a), FDA's conclusion that tobaccoproducts are drugs and devices is subject to review under the standard setforth in Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc.,467 U.S. 837 (1984). Under Chevron, unless Congress has "unambiguouslyexpressed [its] intent" and "directly addressed the precise questionat issue," the question for a court is whether the agency's view isbased on a "permissible construction" of the Act. Id. at 843.That means that "a court may not substitute its own construction ofa statutory provision for a reasonable interpretation made by the administratorof an agency." Id. at 844. Rather, when the agency "fills a gapor defines a term in a way that is reasonable in light of the legislature'srevealed design," a court must give the agency's view "controllingweight." Ibid. As we now demonstrate, FDA reasonably concluded thattobacco products are subject to regulation under the Act as "drugs"and "devices." The Court should therefore give FDA's interpretationcontrolling weight.3
A. FDA's Interpretation Is Supported By The Plain Language, Structure, AndDrafting History Of The Drug And Device Definitions
1. Rather than identifying specific products that FDA may regulate as "drugs"and "devices," Congress enacted comprehensive definitions of thoseterms. Products that fall within those definitions, unless expressly exempted,are subject to the Act's regulatory regime. The Act defines "drug"as:
(A) articles recognized in the official United States Pharmacopoeia, officialHomeopathic Pharmacopoeia of the United States, or official National Formulary,or any supplement to any of them; and (B) articles intended for use in thediagnosis, cure, mitigation, treatment, or prevention of disease in manor other animals; and (C) articles (other than food) intended to affectthe structure or any function of the body of man or other animals; and (D)articles intended for use as a component of any article specified in clauses(A), (B), or (C) of this paragraph.
21 U.S.C. 321(g)(1) (emphasis added). The Act similarly defines "device"as, inter alia, "an instrument, apparatus, * * * contrivance, * * *or other similar or related article, including any component, part, or accessory,* * * intended to affect the structure or any function of the body of manor other animal, and which does not achieve its primary intended purposesthrough chemical action within or on the body and which is not dependentupon being metabolized for the achievement of its primary intended purposes."21 U.S.C. 321(h)(3).
Significantly, the Act does not exempt tobacco from the drug and devicedefinitions. In contrast, the Act does specifically exclude "food"from the very "structure-function" definition of "drug"at issue here, 21 U.S.C. 321(g)(1)(C), and exempts "tobacco" itselffrom the definition of "dietary supplement," 21 U.S.C. 321(ff)(1).See also 21 U.S.C. 321(i) (exempting "soap" from the definitionof "cosmetic"; 21 U.S.C. 321(s) (1994 & Supp. III 1997) (exempting"pesticides" in certain circumstances from the definition of "foodadditive"). Congress has also specifically exempted tobacco productsfrom many other laws, including the Federal Hazardous Substances Act, 15U.S.C. 1261(f)(2), the Fair Packaging and Labeling Act, 15 U.S.C. 1459(a)(1),the Consumer Products Safety Act, 15 U.S.C. 2052(a)(1)(B), the Toxic SubstancesControl Act, 15 U.S.C. 2602(2)(B)(iii), and the Controlled Substances Act,21 U.S.C. 802(6). Accordingly, the overwhelming implication from the textand structure of the "drug" and "device" definitionsis that tobacco products, like all other products not specifically exempted,are subject to regulation as "drugs" and "devices" ifthey are "intended to affect the structure or any function of the body."21 U.S.C. 321(g)(1)(C) and (h)(3).

2. Given the extensive evidence before FDA, and FDA's findings based onthat evidence, tobacco products plainly qualify as "drugs" and"devices" under that statutory standard. The evidence establishedthat: (1) nicotine in tobacco products causes and sustains addiction andacts as a sedative, stimulant, and appetite suppressant; (2) most personswho use tobacco products do so in order to obtain those effects; (3) tobaccomanufacturers know that most consumers use their products for those purposes;(4) tobacco manufacturers themselves characterize nicotine as a powerfuldrug and cigarettes as a vehicle for delivering nicotine; (5) the manufacturersdesign their products to deliver pharmacologically active doses of nicotine;and (6) the manufacturers market their products with claims that they willprovide "satisfaction," a "code-word" for the pharmacologicaleffects of nicotine. See pp. 3-8, supra. Based on that compelling evidence,FDA found that the nicotine in tobacco products is intended by manufacturersto cause and sustain addiction, and to act as a sedative, stimulant, andappetite suppressant. In light of that critical finding, tobacco productsfit squarely within the "drug" and "device" definitions-theyare, without question, "intended to affect the structure or any functionof the body." 21 U.S.C. 321(g)(1)(C) and (h)(3). Thus, the plain languageof the Act, which is the starting point in resolving any question of statutoryconstruction, United States v. Ron Pair Enters., Inc., 489 U.S. 235, 241(1989), provides powerful support for FDA's conclusion that tobacco productsare "drugs" and "devices" under the Act.

3. The history of the Act provides additional support for FDA's conclusion.Before the Act was passed in 1938, the Pure Food and Drugs Act defined "drug"to include "articles recognized in the official United States Pharmacopoeia,official Homeopathic Pharmacopoeia of the United States, or official NationalFormulary, or any supplement to any of them," and "any substanceor mixture of substances intended to be used for the cure, mitigation, orprevention of disease of either man or other animals." Pure Food andDrugs Act of 1906, ch. 3915, § 6, 34 Stat. 769. In the 1938 Act, Congressexpanded the definition of "drug" to include "articles (otherthan food) intended to affect the structure or any function of the bodyof man or other animals." § 201, 52 Stat. 1041. The new Act alsoadded a parallel definition of "device." Ibid. Congress enactedthe new definitions because existing law "contain[ed] serious loopholes"and was "not sufficiently broad in its scope to meet the requirementsof consumer protection under modern conditions." H.R. Rep. No. 2139,75th Cong., 3d Sess. 1 (1938). Congress was particularly concerned aboutdangerous and ineffective weight-loss products that had escaped regulationunder the old drug definition. S. Rep. No. 361, 74th Cong., 1st Sess. Pt.1, at 239 (1935). Congress understood, however, that the Act would reachwell beyond weight-loss products and cover other products intended to affectthe structure or function of the body. See H.R. Rep. No. 2139, supra, at2 ("Drugs intended for diagnosing illness or for remedying underweightor overweight or for otherwise affecting bodily structure or function aresubjected to regulation.").
The drafting history of the drug and device definitions provides compellingevidence that the definitions were intended to have a scope that is as broadas their language prescribes. Early versions of the bill had included "devicesintended to affect the structure or function of the body" within thedefinition of "drug." S. Rep. No. 493, 73d Cong. 2d Sess. 2 (1934).In hearings on one of those bills, a Member of Congress asked the FDA Administratorwhether the drug definition would include "ultraviolet lights and variousinstruments of that sort." Charles W. Dunn, Federal Food, Drug, andCosmetic Act, App. B at 1053 (1938). The Administrator responded that itwould, because the portion of the "drug" definition that encompassed"devices" was "admittedly an inclusive, * * * wide definition."Ibid. The Administrator added that the definition would also encompass beltsused for therapeutic purposes, explaining that "[t]his definition of'drugs' is all-inclusive." Id. App. C at 1126-1127. Members of Congresslater expressed concern that the device portion of the drug definition wasso broad as to reach shoulder braces, radium belts, electrical devices,bathroom weight scales, hospital air conditioners, and crutches. UnitedStates v. Bacto-Unidisk, 394 U.S. 784, 795-796 (1969) (citing relevant debates).The members did not object to the regulation of such products under theAct; instead, they objected to the characterization of such products asdrugs. Id. at 796-797. In response to that narrow concern, the bill wasamended to remove devices from the drug definition and to create a separatedefinition of "device" that paralleled the new definition of drug.Ibid. That solution eliminated the awkwardness of referring to electricbelts and therapeutic lamps as drugs, while preserving the bill's broadscope. Ibid.
The statutory background and drafting history of the Act show that Congressunderstood that the definitions of "drug" and "device"would determine what products would be subject to regulation under the Act,and that the scope of those definitions was intended to be coextensive withtheir plain language, reaching many products that had not been subject toregulation before. Accordingly, they firmly support FDA's reliance on theplain language of the "drug" and "device" definitionsin concluding that, given their intended pharmacological effects, tobaccoproducts are subject to regulation under the Act.4

4. This Court's decision in Bacto-Unidisk also provides significant supportfor FDA's analysis. The question in that case was whether an antibioticsensitivity disc used to determine which antibiotic should be used in treatmentof a particular patient was a "drug" under the Act. 394 U.S. at784. The disc satisfied the literal definition of "drug," becauseit was intended for use in the cure, mitigation, or treatment of disease.Id. at 792. The lower courts had held, however, that the drug definitionshould be construed to reach only those products that satisfy the medicaldefinition of a drug. Ibid. This Court squarely rejected that interpretationand held that the disc was a "drug" within the meaning of theAct. Relying on the text of the Act and the drafting history discussed above,the Court concluded that "the word 'drug' is a term of art for purposesof the Act, encompassing far more than the strict medical definition ofthat word." Id. at 793. The Court further explained that "[t]hehistorical expansion of the definition of drug, and the creation of a parallelconcept of devices, clearly show * * * that Congress fully intended thatthe Act's coverage be as broad as its literal language indicates-and equallyclearly broader than any strict medical definition might otherwise allow."Id. at 798. Bacto-Unidisk therefore fully supports FDA's reliance on theplain language of the drug and device definitions for its conclusion that,in light of their intended pharmacological effects, tobacco products aredrugs and devices under the Act.
B. FDA's Interpretation Is Also Supported By FDA's Prior Regulatory PracticeAnd The Public Health Purposes Of The Act
1. FDA's conclusion that tobacco products are subject to regulation as drugsand devices is also supported by FDA's prior regulatory practice and thepublic health purposes of the Act. As FDA has explained, the intended pharmacologicaleffects of tobacco products mirror those of numerous other products thatFDA regulates, including tranquilizers, stimulants, weight-loss products,and narcotics used to treat addiction. See 61 Fed. Reg. at 44,632, 44,667-44,678.FDA also regulates the sale of other products containing nicotine, suchas nicotine patches, nicotine chewing gum, and nicotine nasal spray, andthe pharmacological effects of nicotine in tobacco products are far morepowerful than those in the other nicotine-containing products. Id. at 44,665.
Significantly, moreover, tobacco products have the classic characteristicsof drugs and devices subject to regulation under the Act: Tobacco productsare taken within the human body, they deliver a pharmacologically activesubstance to the bloodstream, and they have potentially dangerous effects.61 Fed. Reg. at 44,628. The resemblance of tobacco products to other productsregulated as drugs and devices by the FDA has not escaped the attentionof tobacco manufacturers. In their own research, market planning, and deliberations,the manufacturers have referred to the nicotine in tobacco as a drug, tocigarettes as a vehicle for the delivery of nicotine, and to the tobaccoindustry as a segment of the pharmaceutical industry. See pp. 5-7, supra.Because of the similarity between tobacco products and other products regulatedby FDA, it is not surprising that FDA has previously regulated tobacco productswhen it has found sufficient evidence that they were intended to affectthe structure or any function of the body, see United States v. 354 BulkCartons * * * Trim Reducing-Aid Cigarettes, 178 F. Supp. 847, 851 (D.N.J.1959), or that they were intended to treat or prevent disease, see UnitedStates v. 46 Cartons, More or Less, Containing Fairfax Cigarettes, 113 F.Supp. 336, 338-339 (D.N.J. 1953).

2. Respondents have sought to distinguish the products regulated by FDAthat have pharmacological effects similar to those of tobacco products onthe ground that those products are sold with express therapeutic claims.That distinction, in respondents' view, also explains why it was appropriatefor FDA to regulate tobacco products in the two cigarette cases cited above.Under respondents' theory, tobacco products would be subject to FDA regulationonly if tobacco manufacturers suddenly decided on a policy of full publicdisclosure and made express representations that their products cause andsatisfy addiction and are intended to be used as a sedative, stimulant,and appetite suppressant. But as long as they refrain from making such claims,respondents argue, tobacco products are not subject to the Act. That remainstrue, under respondents' theory, even when, as here, there is overwhelmingevidence that consumers use tobacco products as sedatives, stimulants, andappetite suppressants and to maintain addiction; that those characteristicsof tobacco products are so well known as to render them unquestionably foreseeableto the manufacturers of the products; and that the manufacturers of theproducts in fact act keenly aware of those effects and uses and manipulatethe nicotine content of their products to promote them.
In these circumstances, the pervasive knowledge and conduct on the partof both manufacturers and consumers serve the same function as labelingor other express representations by the manufacturers in identifying theintended effects and uses of the product, thereby rendering any such representationsunnecessary. It would be ironic indeed, and contrary to the fundamentalpublic health purposes of the Act, to conclude that a product is altogetherexcluded from regulation under the comprehensive terms of the Act preciselybecause its basic drug-like qualities are so well documented, widely known,and thoroughly embedded in the behavior of consumers and manufacturers asto render express claims to that effect superfluous. And, not surprisingly,respondents' view that FDA must blind itself to compelling evidence thata product is intended to affect the structure or function of the body simplybecause a manufacturer has not made any express claims of therapeutic valueis at odds with the text of the Act, longstanding FDA regulations, the legislativehistory of the Medical Devise Amendments of 1976, lower court decisions,and FDA's regulatory practice.
The text of the Act makes "intended" effects, not "marketclaims," the decisive factor. 21 U.S.C. 321(g)(1)(C) and (h)(3). Whilemarket claims are one important way in which a product's intended effectsmay be established, they are not the only way. As the present case so clearlyshows, other circumstances can establish that a product is intended to affectthe structure or function of the body. Nothing in the text of the operativedefinitions bars FDA from relying on such evidence. Moreover, if Congresshad wished to establish the statutory standard respondents propose, it couldhave used terms such as "promoted to," "labeled to,""advertised to," or "represented to" instead of "intendedto." Congress used such terms in other provisions of the Act. 21 U.S.C.321(n) (misbranding may result from "representations" made in"labeling or advertising"); 21 U.S.C. 352(a) (a drug is misbrandedif its "labeling" is false or misleading); 21 U.S.C. 352(c) (adrug is misbranded unless its "advertisements and other descriptiveprinted matter" contain certain true statements). Congress's failureto use those terms in the drug and device definitions is therefore significant:It shows that Congress understood the difference between intended effectsand claimed effects, and that it deliberately chose the more comprehensive"intended to affect" formulation to define the products subjectto coverage under the Act. See 61 Fed. Reg. at 45,154-45,155.
Consistent with that understanding, FDA regulations that have been in effectfor more than four decades provide that "intended use" (or wordsto that effect) refer to "the objective intent of the persons legallyresponsible for labeling," and may be determined not only by "labelingclaims" and "advertising matter," but also by (1) other "oralor written statements" made by persons legally responsible for thelabeling; (2) "the circumstances surrounding the distribution of thearticle"; (3) "the circumstances that the article is, with theknowledge of [the responsible persons], * * * offered and used for a purposefor which it is neither labeled nor advertised"; and (4) evidence that"a manufacturer knows, or has knowledge of facts that would give himnotice" that a drug or device "is to be used" for purposesother than those for which the manufacturer offered the products. 21 C.F.R.201.128 (drug); 21 C.F.R. 801.4 (device).5 FDA has further explained thatits "objective intent" standard means that FDA will consider allrelevant evidence of intent from the perspective of a reasonable fact-finder,and that it is not bound by the intent a manufacturer claims to have. 61Fed. Reg. at 45,153, 45,184 n.1133. Compare Posters 'N' Things v. UnitedStates, 511 U.S. 513, 519-522 (1994) (holding that the phrase "primarilyintended for use [with illegal drugs]," which is the definition of"drug paraphernalia" in 21 U.S.C. 857(d), "is to be understoodobjectively and refers generally to the item's likely use").
The legislative history of the Medical Device Amendments of 1976, Pub. L.No. 94-295, 90 Stat. 539, in which Congress revised and reenacted the definitionof "device" in its current form, see § 3(a)(i)(A), 90 Stat.575, confirms the soundness of FDA's interpretation of that definition (andthe parallel definition of "drug") as not limiting the "intended"effects of a product to those the manufacturer expressly claims. The HouseReport stated that, although the major new authorities to be conferred onFDA should be limited to devices intended for human use,
[t]his is not to say * * * that a manufacturer of a device that is bannedby the Secretary [for human use] can escape the ban by labeling the devicefor veterinary use. The Secretary may consider the ultimate destinationof a product in determining whether or not it is for human use, just ashe may consider actual use of a product in determining whether or not itis a device.
H.R. Rep. No. 853, 94th Cong., 2d Sess. 14 (1976) (emphasis added).
Lower courts likewise have agreed that a manufacturer's intent with respectto effects or use may be determined on the basis of all relevant circumstances,including consumer use, not simply a manufacturer's market claims. NationalNutritional Foods Ass'n v. Mathews, 557 F.2d 325, 334 (2d Cir. 1977) (intentmay be determined from any relevant source, including consumer use); UnitedStates v. An Article * * * Consisting of * * * 216 Cartoned Bottles, 409F.2d 734, 739, 742 (2d Cir. 1969) (the intended use of a product may bedetermined from its label, accompanying labeling, promotional material,advertising and any other relevant source, including consumer use); UnitedStates v. Storage Spaces Designated Nos. "8" & "49",777 F.2d 1363, 1366 (9th Cir. 1985), (manufacturer intent may be derivedfrom any relevant source), cert. denied, 479 U.S. 1086 (1987); Action onSmoking & Health v. Harris, 655 F.2d 236, 239-240 (D.C. Cir. 1980) (ASH)(consumer use can be relevant in determining manufacturer intent); see alsoUnited States v. 789 Cases * * * of Latex Surgeons' Gloves, 799 F. Supp.1275, 1285, 1294-1295 (D.P.R. 1992); United States v. An Article of Device* * * "Cameron Spitler Amblyo-Syntonizer", 261 F. Supp. 243, 245(D. Neb. 1966). From a public health perspective, no other result couldbe justified. The risks to the public health and the appropriateness ofregulation under the Act exist regardless of whether intended effects areestablished through market claims or by other evidence. See Bacto-Unidisk,394 U.S. at 798 (the Act is to be given a construction "consistentwith the Act's overriding purpose to protect the public health").
Finally, in its administration of the Act, FDA has treated products intendedto affect the structure or function of the body as drugs or devices, despitethe absence of express market claims of therapeutic value. For example,FDA took enforcement action against "caine," a product that containedanesthetic powders and that was often marketed as incense. FDA found that"caine" was intended to be used as a drug, based on a laboratoryanalysis of its ingredients, its sale in "head shops," and "street"information that it provided a "cheap high." 61 Fed. Reg. at 45,167.Similarly, FDA took enforcement action against "khat," a shrubwhose leaves act as a stimulant when chewed or used as tea, even thoughits vendors did not make any market claims. FDA determined that "khat"was intended for use as a drug based on its actual effects and widely knownuses. Ibid.
FDA has also treated other products as drugs or devices, despite the absenceof explicit market claims. Among other products, FDA has treated as drugsor devices: (1) cosmetics containing hormones based on the absence of anylegitimate cosmetic purpose for the hormones; (2) toothpaste containingfluoride because fluoride is widely accepted as an anti-cavity agent andaffects the structure of the tooth; (3) thyroid-containing food supplementsbased on the recognized physiological effects of thyroid products; (4) interferonbased on media coverage touting it as a possible miracle cure; (5) noveltycondoms based on their likely use as prophylactics; (6) noncorrective tintedcontact lenses based on their effects on the eye; (7) sunscreen productsbased on consumer expectations that they will provide protection againstthe sun; and (8) tanning booths based on the known effects of ultravioletrays. 60 Fed. Reg. at 41,528-41,531. In each of the above cases, FDA foundthat the product was intended for use as a drug or a device based on theinherent nature of the product, its predominant use or effects, or both.Id. at 41,527. There is no principled basis for treating tobacco productsdifferently, especially in light of the compelling evidence that tobaccomanufacturers have known for decades that nicotine is addictive and hasmood-altering effects and that those are the main reasons that people usetobacco products. Tobacco products should not escape regulation for theprotection of the public health simply because tobacco manufacturers rerainfrom making express claims about the pharmacological effects and uses theyso clearly intend and from which they so clearly profit.
C. FDA's Interpretation Is Consistent With The Structure Of The Act As AWhole
The court of appeals rejected FDA's conclusion that tobacco products aredrugs and devices in large part because it believed that regulation of tobaccoproducts is inconsistent with the structure of the Act as a whole. The courtessentially reasoned as follows: (1) If tobacco products are drugs or deviceswithin the meaning of the Act, the regulatory provisions of the Act wouldrequire them to be banned; (2) Congress did not intend for tobacco productsto be banned; therefore (3) tobacco products are not drugs and devices.See generally Pet. App. 18a-30a. That analysis is seriously flawed. FDAreasonably concluded that the operative regulatory provisions of the Actdo not require a ban of tobacco products. Even if the operative provisionsof the Act were to require a ban, however, that would not detract from thereasonableness of FDA's conclusion that tobacco products are drugs and devices.
1. In concluding that tobacco products would have to be banned if they aredrugs and devices, the court of appeals cited provisions of the Act thateither directly prohibit the marketing of drugs and devices that FDA hasfound not to be sufficiently "safe," or contemplate that FDA willprevent or otherwise regulate the marketing of such products.6 Because FDAdetermined that tobacco products are dangerous, the court reasoned, thoseprovisions would require tobacco products to be banned if they were "drugs"and "devices." See generally Pet. App. 18a-30a.
In deciding whether a drug or device is sufficiently "safe" withinthe meaning of the provisions cited by the court of appeals, however, FDA'srole is not confined to determining whether the product is unsafe as thatterm is most commonly used. FDA also generally weighs the risk presentedby a product against countervailing health benefits. That balancing of risksand benefits is expressly required when FDA classifies devices into regulatorycategories. 21 U.S.C. 360c(a)(2)(C) ("the safety and effectivenessof a device are to be determined by weighing any probable benefit to healthfrom the use of the device against any probable risk of injury or illnessfrom such use"). FDA also follows the same general balancing approachin applying and enforcing other provisions of the Act. See United Statesv. Rutherford, 442 U.S. 544, 555 (1979). For example, as FDA has explained,several products used in the treatment of cancer are highly toxic and thereforeare not "safe" as that term is most commonly understood. 61 Fed.Reg. at 44,413. FDA has nonetheless approved such products for use in cancertreatment after finding that the danger of not treating the cancer outweighsthe risks of the drugs. Ibid.
FDA applied a similar analysis here. It found that, while "tobaccoproducts are unsafe as that term is conventionally understood," theAct contemplates "consideration of not only the risks presented bya product but also any of the countervailing effects of use of that product,including the consequences of not permitting the product to be marketed."61 Fed. Reg. at 44,412-44,413. After undertaking that balancing process,FDA concluded that, with respect to adults, "the sudden withdrawalfrom the market of products to which so many millions of people are addictedwould be dangerous" for several reasons. Id. at 44,413. First, as aresult of withdrawal symptoms, "[t]here could be significant healthrisks to many of these individuals." Ibid. Second, the health caresystem could be "overwhelmed by the treatment demands that these peoplewould create, and it is unlikely that the pharmaceuticals available couldsuccessfully treat the withdrawal symptoms of many tobacco users."Ibid. Finally, because of the strength of the addiction and the difficultyof quitting, "a black market and smuggling would develop to supplysmokers with these products," and the black market products would likely"be even more dangerous than those currently marketed, in that theycould contain even higher levels of tar, nicotine, and toxic additives."Ibid. FDA therefore reasonably concluded that, "on balance, an approachthat prohibits the sale and promotion of cigarettes and smokeless tobaccoto children and adolescents, while permitting the sale to adults seems mostappropriate, * * * is consistent with the statutory standard of reasonableassurance of safety[,] and is more effective in achieving public healthgoals than a ban on all tobacco products." Ibid.
The Fourth Circuit rejected FDA's analysis on the ground that FDA had appliedthe wrong legal standard for determining the safety of a product. In thecourt's view, the Act requires FDA "to strike a balance between therisks and benefits of the use of a product, not to weigh the risks of leavinga product on the market against the risks of taking a product off the market."Pet. App. 21a. The statutory text, however, does not impose any such limitationon the agency's discretion. The "benefit to health from the use"of a product, 21 U.S.C. 360c(a)(2)(C), readily encompasses the preventionof the harmful health consequences that would ensue if a product were removedfrom the market. Tobacco products thus "benefit" the "health"of many users because they relieve otherwise untreatable symptoms of nicotinewithdrawal, and because they are safer than black market products that wouldpredictably be used for that purpose if tobacco products could no longerbe lawfully marketed to adults.
FDA's interpretation, moreover, best comports with the public health purposesof the Act. From a public health perspective, it would make no sense torequire removal of a product from the market when that would cause moreharmful health consequences than leaving the product on the market. ThisCourt's decision in Rutherford also supports FDA's interpretation. There,the Court affirmed FDA's conclusion that laetrile, while inherently harmless,was unsafe within the meaning of the Act and should be removed from themarket, because its availability could lead persons to reject more beneficialconventional treatments. 442 U.S. at 556. FDA's conclusion here-that thecontinued marketing of tobacco products to adults should be allowed becausetheir removal could leave those users without treatment alternatives fortheir addiction and lead them to use more dangerous products-is the mirrorimage of the analysis approved in Rutherford. Thus, FDA's conclusion thatthe Act does not require tobacco products to be banned is based on a reasonableconstruction of the Act. Under Chevron, the court of appeals should havedeferred to it. The court of appeals, however, did not even advert to thequestion of Chevron deference when it rejected FDA's conclusion that theAct does not require it to impose a complete ban on tobacco products. SeePet. App. 20a-30a.

2. Even assuming the regulatory provisions of the Act would require tobaccoproducts to be banned, however, that would not affect the reasonablenessof FDA's conclusion that tobacco products are drugs and devices within themeaning of the Act. As Judge Hall stated in his dissent in this case, "[h]owthe FDA has chosen to regulate tobacco has no bearing on the question ofwhether that agency has the authority to regulate it at all." Pet.App. 60a-61a. See also Bacto-Unidisk, 394 U.S. at 792 (while the partieshave debated the wisdom of subjecting antibiotic sensitivity disks to premarketreview, the only relevant inquiry "is whether the statute's definitionof 'drug' authorizes the disc regulations contested here").
The court of appeals' contrary conclusion rests on the premise that a banon tobacco products would be a consequence that the enacting Congress didnot contemplate and that therefore would conflict with Congress's intent,so that, if the regulatory provisions of the Act would require tobacco productsto be banned, they cannot be drugs or devices. No provision of the Act aspassed in 1938, however, suggests that a ban on the sale of tobacco products,or indeed any other products-based on powerful evidence that might latercame to light establishing the addictive and other intended pharmacologicaleffects of such products-would conflict with congressional intent. Nor isthere any other sound basis for reaching that conclusion.
Congress expresses its operative intent in the text of the laws it enacts,see Oncale, 523 U.S. at 79-80; H.J. Inc., 492 U.S. at 248, and that intentis not difficult to discern here: When FDA finds that a product is "intendedto affect the structure or any function of the body", 21 U.S.C. 321(g)(1)(C)and (h)(3), and that the product is not sufficiently, "safe,"21 U.S.C. 393(b)(2)(B) and (C)-i.e., the risks of the product outweigh itsbenefits-Congress intended for the product not to be marketed.7
If this Court were to overturn FDA's judgment that the risks of tobaccoproducts are outweighed by the countervailing benefits of continued marketingto adults, that would simply mean that the Act, as presently written, requirestobacco products to be banned. That consequence, however, would in no wayundermine FDA's conclusion that tobacco products are intended to affectthe structure or function of the body and are therefore drugs and devicessubject to regulation under the Act. In those circumstances, then, it wouldproperly be for Congress, after weighing the competing considerations, todecide whether the ban that was (by hypothesis) required by the Act in itscurrent form should remain in effect, or whether the Act should be amendedto permit the continued marketing of cigarettes and other tobacco products,under whatever conditions Congress might then prescribe. That result wouldnot be at all anomalous in the working of a comprehensive, prophylacticstatute designed to protect the public health and safety. It is, for example,the way in which the Food, Drug, and Cosmetic Act itself operated and Congressresponded after FDA concluded that saccharin is an animal carcinogen, thecontinued sale of which as a food additive would be unlawful under the Act,a conclusion that was dictated by the Delaney Clause, 21 U.S.C. 348(c)(3).Congress enacted legislation that imposed an 18-month moratorium on FDA'sproposed rule. Saccharin Study and Labeling Act, Pub. L. No. 95-203, 91Stat. 1451.8 That moratorium has been extended repeatedly, and it remainsin effect today. See Pub. L. No. 104-180, § 602, 110 Stat. 1594; 21U.S.C. 348 note.9
D. FDA's Prior Statements, Unenacted Tobacco Bills, And Certain Tobacco-SpecificStatutes Enacted Long After 1938 Do Not Detract From The ReasonablenessOf FDA's Interpretation
In rejecting FDA's conclusion that tobacco products are drugs and devices,the court of appeals also relied on FDA's prior statements concerning itsauthority to regulate tobacco products, unenacted bills that would havespecifically authorized FDA to regulate tobacco products, and certain tobacco-specificstatutes enacted long after the Federal Food, Drug, and Cosmetic Act waspassed. FDA carefully examined each of those sources and reasonably determinedthat they do not detract from the conclusion that tobacco products are drugsand devices under the Act.
1. Until FDA issued the regulations at issue here, the only instances inwhich the agency had found that tobacco products were drugs involved casesin which there were express market claims of therapeutic value. FDA's priorposition on the subject was authoritatively expressed in decisions in 1977and 1980 rejecting petitions filed by Action on Smoking in Health (ASH)to regulate cigarettes as drugs or devices. See J.A. 44-49 (Letter fromFDA Commissioner Kennedy to ASH Executive Director Banzhaf (Dec. 5, 1977));J.A. 50-68 (Letter from FDA Commissioner Goyan to ASH Executive DirectorBanzhaf (Nov. 25, 1980)). Focusing on those decisions, and some earlierstatements made by FDA officials, the court of appeals treated FDA's currentposition as not warranting deference. Pet. App. 31a-37a. The court of appealserred both in its understanding of FDA's prior position and in its approachto reviewing FDA's current regulation of tobacco products.
An agency's position on any given issue is not "carved in stone."Chevron, 467 U.S. at 863. To fulfill its assigned responsibilities, an agency"must be given ample latitude to 'adapt [its] rules and policies tothe demands of changing circumstances,'" Motor Vehicle Mfrs. Ass'nv. State Farm Mut., 463 U.S. 29, 42 (1983), and "must consider varyinginterpretations and the wisdom of its policy on a continuing basis."Chevron, 467 U.S. at 863-864. For those reasons, and because "the wholepoint of Chevron is to leave the discretion provided by the ambiguitiesof a statute with the implementing agency," Smiley v. Citibank (SouthDakota), N.A., 517 U.S. 735, 742 (1996), an agency is always free to changeits position on an issue or its interpretation of a statute, as long asit offers a "reasoned analysis" that justifies the change. Rustv. Sullivan, 500 U.S. 173, 187 (1991); Chevron, 467 U.S. at 863-864; MotorVehicle Mfrs. Ass'n, 463 U.S. at 42.
FDA provided such a "reasoned analysis" here. Specifically, FDAexplained that three key developments led to its change in position. First,while no major health organization had determined that nicotine was an addictivedrug before 1980, by 1994, every leading scientific panel or organizationhad concluded that nicotine is addictive. 61 Fed. Reg. at 45,228. Second,since 1980, scientific evidence has shown that an overwhelming percentageof users of tobacco products do so to satisfy their addiction and to obtainnicotine's mood-altering effects. Id. at 45,233-45,234. In contrast, before1980, there was no evidence regarding the proportion of users who were addicted,and the evidence was insufficient to conclude that tobacco products wereconsumed primarily for their pharmacological effects. Id. at 45,234-45,235.Third, recently released internal industry documents show that tobacco manufacturershave long known that consumers use tobacco products to sustain addictionand for other pharmacological effects, and that manufacturers have deliberatelyengineered their products to deliver active doses of nicotine. Id. at 45,235-45,236. Almost none of that evidence was publicly available in 1980. Id.at 45,237. FDA's finding that tobacco products are intended to affect thestructure and function of the body, regardless of whether they are accompaniedby express market claims of therapeutic value, is therefore "basedon an overwhelming body of new evidence that ha[d] become available sinceFDA last considered this issue." Id. at 45,237. Because FDA provideda reasoned explanation for its change in position, that position is entitledto full Chevron deference. Rust, 500 U.S. at 186-187; Motor Vehicle Mfrs.Ass'n, 463 U.S. at 42; see also Smiley, 517 U.S. at 742.
The court of appeals concluded that FDA's prior decisions not to regulatetobacco products were based on a categorical view that tobacco productscannot be subject to regulation under the Act absent specific health claims,rather than the absence of the kind of evidence of intended effects discussedabove. Pet. App. 36a. The court's understanding of the ASH decisions isincorrect. In the 1977 decision, FDA rejected ASH's assertion that cigarettescould be regulated as drugs because consumers use them for their effectson the body, on the ground that ASH's evidence was not sufficient to establishsuch an intent by the manufacturers or vendors of cigarettes. J.A. 48-49.The government's brief defending FDA's decision in the court of appealsexplained that FDA had concluded that cigarettes could not be regulatedas drugs "in the absence of health claims by the manufacturers or vendorsor other evidence of the manufacturers' or vendors' intent to affect thebodily structure or functions." Gov't Br. at 14, Action on Smoking& Health v. Harris, 655 F.2d 236 (D.C. Cir. 1980) (emphasis added).In affirming FDA's decision, the D.C. Circuit stated that "we do notread [FDA's decision] to mean either that the Commissioner will never considerevidence of consumer intent on this question or that he simply ignored theevidence presented to him in this petition." ASH, 655 F.2d at 239.Instead, the petition failed because ASH had failed to "meet the highstandard established in cases where the statutory 'intent' is derived fromconsumer use alone." Ibid.
In the 1980 "device" decision, FDA stated that the relevant inquiryunder the Act is whether there "is objective evidence that the manufactureror vendor intends that the article is to affect the structure or a functionof the body." J.A. 56. FDA further explained that a finding of suchan intent could be based not only on a manufacturer's market claims, butalso on "the circumstances surrounding [a product's] distribution,"and the "consumer intent in using a product." Ibid. FDA determined,however, that ASH's evidence, including ASH's evidence of consumer use,"fails to establish that cigarettes are intended 'to affect the structureor any function of the body.'" J.A. 57; accord J.A. 61-63. FDA's priorrulings on formal petitions to regulate tobacco products therefore restedon the absence of sufficient evidence at the time that such products wereintended to affect the structure or function of the body-not on a categoricalview that tobacco products can satisfy the drug and device definitions onlyif manufacturers make express market claims of therapeutic value.10
Even if FDA's prior decisions not to regulate tobacco products could beunderstood as resting on such a categorical view, however, that would notaffect the validity of FDA's present determination that tobacco productsare drugs and devices under the Act. An agency is not only free to alterits view of the underlying facts; it is also free to change its view ofthe appropriate legal standard for evaluating the facts. See Rust, 500 U.S.at 186-187. Regardless of whatever uncertainty there might have been aboutFDA's position in the past, FDA has now unambiguously concluded that thedrug and device definitions encompass products that are intended by manufacturersto affect the structure or function of the body, irrespective of whetherthe manufacturer makes express claims of therapeutic value. FDA has alsoconcluded that there is no basis for creating an exception to that legalstandard for tobacco products. Because that interpretation of the Act issupported by a "reasoned analysis," it is entitled to full Chevrondeference. Ibid.

2. Over the years, Congress has failed to enact bills that would have expresslyauthorized FDA to regulate tobacco products. The court of appeals viewedsuch congressional inaction as strong evidence that FDA lacks authorityto regulate tobacco products under the Act. Pet. App. 37a-39a. Failed legislativeproposals, however, do not furnish a sound basis for determining the meaningof a prior statute. See, e.g., United States v. Estate of Romani, 523 U.S.517, 533-535 (1998); Central Bank v. First Interstate Bank, 511 U.S. 164,187 (1994). The Constitution requires Congress to express its will throughenacted legislation, not unenacted bills. INS v. Chadha, 462 U.S. 919, 945-959(1983). Congressional inaction also "lacks persuasive significancebecause several equally tenable inferences may be drawn from such inaction,including the inference that the existing legislation already incorporatedthe offered change." Central Bank, 511 U.S. at 187 (quoting PensionBenefit Guar. Corp. v. LTV Corp., 496 U.S. 633, 650 (1990)). For those reasons,Congress's failure to enact bills that would have expressly authorized FDAto regulate tobacco products has no more bearing on the question presentedin this case than does Congress's failure to enact bills that would haveexcluded tobacco products from the reach of the Act, e.g., S. Rep. No. 1295,104th Cong., 1st Sess. (1995); H.R. Rep. No. 2283, 104th Cong., 1st Sess.(1995), or Congress's failure during the past three years to overturn FDA'sdecision to regulate tobacco products.
The court of appeals' reason for attributing significance to the legislativeinaction at issue here is particularly unconvincing. In the court's view,such inaction amounted to congressional "ratification" of FDA'sprior statements and decisions that tobacco products are not subject toregulation under the Act. Pet. App. 37a. As we have explained, however,FDA's prior position was based on the absence of sufficient evidence showingthat tobacco products were intended by manufacturers to affect the structureor any function of the body. Ratification of that position would not reflectany congressional view on whether tobacco products would be covered by theAct if new evidence established that they are intended by manufacturersto be used for sustaining addiction and for sedation, stimulation, and weightcontrol.
More fundamentally, congressional inaction can never affect the authorityof an agency under Chevron to alter its position on an issue. Motor VehicleManufacturers Ass'n, supra, is controlling on that point. In that case,the Court held that Congress's failure to overturn an agency regulationdid not affect the scope of the agency's authority to rescind the regulation.463 U.S. at 44-45. The Court explained that the standard for reviewing agencyaction is not "enlarged or diminished by subsequent congressional action,"and that "even an unequivocal ratification-short of statutory incorporation-* * * would not connote approval or disapproval of an agency's later decisionto rescind the regulation." Id. at 45. Under the analysis in MotorVehicle Manufacturers Ass'n, Congress's failure to overturn FDA's priorposition has no bearing on the validity of FDA's present position that tobaccoproducts are drugs or devices under the Act.

3. Since the Surgeon General issued his well-known report in 1964, Congresshas enacted several statutes that deal with tobacco products in certainspecific respects. See Pet. App. 39a-42a. None of the statutes, however,expressly exempts tobacco products from the reach of the Act. Nor is thereany irreconcilable conflict between the subsequent statutes and the conclusionthat tobacco products fall within the reach of the Act. TVA, 437 U.S. at189-190 (implied repeal occurs only when there is an irreconcilable conflictbetween the old and the new laws). Those statutes therefore do not affectthe reasonableness of FDA's conclusion that tobacco products are drugs anddevices under the Act.
a. The Federal Cigarette Labeling and Advertising Act (FCLAA), 15 U.S.C.1331 et seq., requires cigarette packaging and advertising to bear specificwarnings from the Surgeon General concerning the adverse health effectsof smoking. 15 U.S.C. 1333. FCLAA also contains a specific preemption sectionthat provides that "[n]o statement relating to smoking and health,other than the statement required by section 1333 * * *, shall be requiredon any cigarette package." 15 U.S.C. 1334(a). That statutory text makesclear that FDA may not require warning labels on cigarettes that are differentfrom those required by FCCLA. The text of FCCLA does not remotely suggest,however, that it altogether deprives FDA of any authority to regulate tobaccoproducts. As this Court explained in Cipollone v. Liggett Group, Inc., 505U.S. 504, 518 (1992), FCLAA "merely prohibit[s] state and federal rulemakingbodies from mandating particular cautionary statements on cigarette labels."
The court of appeals derived a broader preemptive scope from FCLAA's statementof policy, which is, inter alia, "to establish a comprehensive Federalprogram to deal with cigarette labeling and advertising with respect toany relationship between smoking and health, whereby * * * commerce andthe national economy may be protected to the maximum extent consistent withthis declared policy and * * * not impeded by diverse, nonuniform, and confusingcigarette labeling and advertising regulations with respect to any relationshipbetween smoking and health." 15 U.S.C. 1331. From that statement, thecourt concluded that Congress had a broad purpose to protect the nationaleconomy by allowing the continued marketing of cigarettes if the packagesbear sufficient warning labels-a goal the court believed would be underminedif tobacco products were "drugs" and "devices" subjectto regulation under the Act. Pet. App. 43a-44a.
As we have already explained, however, treatment of tobacco products asdrugs or devices does not lead to the conclusion that such products mustbe banned, and the regulations at issue here permit the continued sale oftobacco products to adults. In any event, FCLAA does not seek to protectthe national economy by shielding tobacco products from laws that wouldrestrict their marketing. Instead, as the text of FCLAA's policy statementmakes clear, and as its narrow preemption provision confirms, Congress'sgoal was far more limited: It wanted to "protect[] the national economyfrom the burden imposed by diverse, nonuniform, and confusing cigarettelabeling and advertising regulations." Cipollone, 505 U.S. at 514;see Banzhaf v. FCC, 405 F.2d 1082, 1089 (D.C. Cir. 1968) ("[n]othingin the [FCLAA] Act indicates that Congress had any intent at all with respectto other types of regulation by other agencies-much less that it specificallymeant to foreclose all such regulation"), cert. denied, 396 U.S. 842(1969). FCLAA does not limit the authority of FDA to ban the sale of tobaccoproducts, any more than it limits the authority of a State to do so (asindeed all States have done with respect to sales to minors, 61 Fed. Reg.at 44,441). The enactment of FCLAA therefore does not affect the validityof FDA's conclusion that tobacco products are drugs and devices under theAct.
b. The Comprehensive Smokeless Tobacco Health Education Act of 1986 (SmokelessTobacco Act), 15 U.S.C. 4401 et seq., requires warnings on smokeless tobaccopackages that are similar to the warnings required on cigarette packages.15 U.S.C. 4402(a) and (b). It also contains a similar express preemptionprovision, which states: "No statement relating to the use of smokelesstobacco products and health, other than the statements required by section4402 of this title, shall be required by any Federal agency to appear onany package or in any advertisement." 15 U.S.C. 4406(a). Like FCCLA,the Smokeless Tobacco Act simply requires certain warning labels on packagesand precludes federal agencies, including FDA, from requiring differentones. Like FCCLA, the Smokeless Tobacco Act does not in any way suggestthat tobacco products cannot be drugs or devices under the Act.
c. The Alcohol and Drug Abuse Amendments of 1983, Pub. L. No. 98-24, 97Stat. 178, 42 U.S.C. 290aa et seq., direct the Secretary of Health and HumanServices to report to Congress every three years on "the health consequences* * * of drug abuse in the United States [and] * * * current research findingsmade with respect to drug abuse, including current findings on * * * theaddictive property of tobacco," and to include the Secretary's recommendationsfor "legislation and administrative action as the Secretary may deemappropriate." 42 U.S.C. 290aa-2(b). Those reporting requirements donot conflict with FDA's conclusion that tobacco products are drugs and devicesunder the Federal Food, Drug, and Cosmetic Act. As Judge Hall explained,the reporting obligations do no more than acknowledge the important rolethat the Secretary has in determining policy in the complex field of drugabuse, and require the Secretary "to ask Congress for any additionaltools * * * needed to * * * perform that role effectively." Pet. App.69a.
d. The Alcohol, Drug Abuse, and Mental Health Administration ReorganizationAct (ADAMHA), Pub. L. No. 102-321, 106 Stat. 394, created separate blockgrants for state mental health services and drug and alcohol abuse programs.One condition for receiving a block grant is that a State must have in effecta law making it illegal to sell or distribute tobacco products to childrenunder age 18. 42 U.S.C. 300x-26(a). Neither the ADAMHA as a whole nor thatspecific requirement implies that FDA has no authority to regulate tobaccoproducts as a drug or a device.
The court of appeals concluded that, if tobacco products are "drugs"or "devices" subject to regulations under the Federal Food, Drug,and Cosmetic Act, then one provision of that Act, 21 U.S.C. 360k(a) "wouldprohibit States from addressing the problem of youth access," in conflictwith the congressional intent evident in ADAMHA. Pet. App. 51a. Under Section360k(a), a State may not establish "any requirement" with respectto devices that is "different from, or in addition to, any requirementapplicable under" the Act. 21 U.S.C. 360k(a)(1). Section 360k(a), however,"does not preempt State or local requirements that are equal to, orsubstantially identical to, requirements imposed by or under the act."Medtronic, Inc. v. Lohr, 518 U.S. 470, 496-497 (1996) (quoting 21 C.F.R.808.1(d)(2)). Since ADAMHA's "age 18" restriction is the sameas the access restriction imposed by FDA's regulations, the regulationswill not prevent States from complying with their block grant obligationsunder ADAMHA. In fact, by providing an additional level of enforcement againstthe sale of tobacco products to children, the regulations will "facilitatethe end result that Congress sought" in ADAMHA. 61 Fed. Reg. at 44,547.
FDA's regulations could potentially preempt state regulations that imposestricter conditions on the sale of tobacco products than those set forthin the regulations. But that result does not suggest that there is any inherentor irreconcilable conflict between ADAMHA and FDA's conclusion that tobaccoproducts are covered under the Federal Food, Drug, and Cosmetic Act. ADAMHAdoes not provide a protective shield for all state regulations of tobacco.It simply establishes one condition for receiving a block grant, and, asnoted above, FDA's regulations do not prevent States from complying withthat condition. In any event, under 21 U.S.C. 360k(b), States may applyfor an exemption from the preemptive force of the Act, and FDA has substantialdiscretion to grant such an exemption. See 61 Fed. Reg. at 44,550; Medtronic,518 U.S. at 482 n.5, 496. Thus, like the other later-enacted statutes, ADAMHAdoes not impose any impediment to FDA's thoroughly documented and reasonedconclusion that tobacco products are "drugs" and "devices"within the meaning of the Federal Food, Drug, and Cosmetic Act.