When the Controlled Substances Act was passed by Congress in 1970, among its provisions were the classification of various substances and drugs into a series of five schedules. These are Schedule I, II, II, IV, and V. The schedules are arranged in descending order from substances with the highest potential for abuse to least. The lists are updated and published on an annual basis.
The classification for Schedule III substances and drugs stipulates that they have a potential for abuse less than the drugs or other substances in Schedule II. It also stipulates that the drug or substance has a currently accepted medical use in treatment in the United States and abuse of the drug or other substances may lead to moderate or low physical dependence or high psychological dependence.
Examples of Schedule III controlled drugs and substances include anabolic steroids, buprenorphine (Subutex, Suboxone), Testosterone, Chlorhexadol (Mechloral, Mecoral, Melodorm, Chloralodol), Hydrocodone combination product (Lorcet, Lortab, Vicodin, Vicoprofen) and Ketamine (Ketaset, Ketalar, Special K, K).
For the most complete current listing, check the U.S. Department of Justice, Drug Enforcement Agency website. The substance or drug name appears first, with other names, if any, in parentheses.