For about two decades, the National Institute on Drug Abuse (NIDA) has been providing the scientific research community working on problems of drug abuse with authentic, standardized supplies of controlled research drugs and chemicals. Such drugs and chemicals include marijuana and marijuana cigarettes, various cannabinoids, known hallucinogens, heroin, amphetamines, and many others that are essential for pre-clinicla and clinical research. The number of controlled drug substances and other chemicals including opioid peptides that are currently supplied for research has grown significantly because of increasing demand due to a combination of factors including increased regulatory requirements that tend to discourage commercial availability and rapidly expanding research efforts in the area of drug abuse. In order to meet demand for authentic peptides, NIDA plans to continue to maintain an inventory of about 53-55 peptides and some of their respective radio labeled peptides (30-35) for use in NIDA supported studies.