From the Summary: "This report highlights certain non-criminal regulatory requirements of the Controlled Substances Act (CSA). The CSA and its implementing regulations establish a framework through which the federal government regulates the use of controlled substances for legitimate medical, scientific, research, and industrial purposes, and prevents these substances from being diverted for illegal purposes. The CSA assigns various plants, drugs, and chemicals (such as narcotics, stimulants, depressants, hallucinogens, and anabolic steroids) to one of five schedules based on the substance's medical use, potential for abuse, and safety or dependence liability. Schedule I contains substances that have no currently accepted medical use and cannot safely be made available to the public under a prescription, while Schedules II, III, IV, and V include substances that have recognized medical uses and may be manufactured, distributed, and used in accordance with the CSA. The order of the schedules reflects substances that are progressively less dangerous and addictive. To restrict access to chemicals used in the illicit manufacture of certain controlled substances, the CSA also regulates 40 'listed chemicals.' Furthermore, the CSA regulates controlled substance 'analogues,' which are substances that are not controlled but are structurally or pharmacologically similar to substances found in Schedule I or II and have no accepted medical use."
CRS Report for Congress, RL34635