"Enacted in 1970, the CSA [Controlled Substances Act] establishes a statutory framework through which the federal government regulates the lawful production, possession, and distribution of controlled substances.7 The CSA places various plants, drugs, and chemicals (such as narcotics, stimulants, depressants, hallucinogens, and anabolic steroids) into one of five schedules based on the substance’s medical use, potential for abuse, and safety or dependence liability.8 Further, the act requires persons who handle controlled substances or listed chemicals (such as drug manufacturers, wholesale distributors, doctors, hospitals, pharmacies, and scientific researchers) to register with the Drug Enforcement Administration (DEA) in DOJ, which administers and enforces the CSA.9 Registrants must maintain detailed records of their respective controlled substance inventories, as well as establish adequate security controls to minimize theft and diversion.10"

Source

Garvey, Todd, "Medical Marijuana: The Supremacy Clause, Federalism, and the Interplay Between State and Federal Laws," Congressional Research Service (Washington, DC: Library of Congress, March 6, 2012), p. 2.