The three major international drug control treaties are mutually supportive and complementary. An important purpose of the first two treaties is to codify internationally applicable control measures in order to ensure the availability of narcotic drugs and psychotropic substances for medical and scientific purposes, and to prevent their diversion into illicit channels. They also include general provisions on illicit trafficking and drug abuse.

• Single Convention on Narcotic Drugs, 1961 »
• Convention on Psychotropic Substances, 1971 »
• Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, 1988 »