See S. Rep. No. 73-493, at 2-3 (1934) ("The use to which a product is put will determine the category into which it will fall . . . . The manufacturer of this article, through his representations in connection with its sale, can determine the use to whcih an article is to be put."). The mere presence of a chemically active substance would not satisfy this definition; the intended use of the substance must serve a diagnostic or therapeutic purpose or otherwise affect the structure or function of the body. Conversely, a chemically inert substance can qualify as a drug depending on the claims made for it. Thus, bottled water, which would normally be regulated by FDA as a food (and also by the EPA under a different statute) might be regulated (1) as a drug if labeled as a cure for cancer, (2) as a medical device (accessory) if labeled as a sterilizing agent for surgical instruments, or (3) as a cosmetic if labeled as a skin softener. See Bradley v. United States, 264 F. 79, 81-82 (5th Cir. 1920) (holding that curative claims for mineral water made it a "drug").
The intended use of a product typically is determined by its labeling and any other promotional claims made by the seller. See, e.g., United States v. Article of Drug . . . B-Complex Cholinos Capsules, 362 F.2d 923, 925-26 (3d Cir. 1966) (radio broadcasts); Nature Food Centres, Inc. v. United States, 310 F.2d 67, 70 (1st Cir. 1962) (public lectures); V.E. Irons, Inc. v. United States, 244 F.2d 34, 44 (1st Cir. 1957) (oral representations made by authorized sales distributors).
More controversially, the FDA has suggested that "intended use" may include the seller's subjective intent even if never communicated to consumers, which would mean that promotional claims provide the best but no exclusive evidence of a product's intended use. See Richard M. Cooper, The WLF Case Thus Far, 55 Food & Drug L.J. 477, 485-86 (2000) (criticizing this interpretation); see also Meza v. Southern Cal. Physicians Ins. Exchange, 73 Cal.Rptr.2d 91, 94 (Ct. App. 1998) (concluding that melaleuca oil used by a physician to treat warts qualified as a drug even though the seller made no therapeutic claims).
