Drug Efficacy Study Implementation (DESI) was a program begun by the Food and Drug Administration

Food and Drug Administration

The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...

 (FDA) in the 1960s after the requirement (in the Kefauver-Harris Drug Control Act

Kefauver Harris Amendment

The U.S. Kefauver Harris Amendment or "Drug Efficacy Amendment" is a 1962 amendment to the Federal Food, Drug, and Cosmetic Act.It introduced a requirement for drug manufacturers to provide proof of the effectiveness and safety of their drugs before approval...

) that all drug

Drug

A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...

s be efficacious as well as safe. The DESI program was intended to classify all pre-1962 drugs that were already on the market as either effective, ineffective, or needing further study. The Drug Efficacy Study Implementation (DESI) evaluated over 3000 separate products and over 16,000 therapeutic claims. By 1984, final action had been completed on 3,443 products; of these, 2,225 were found to be effective, 1,051 were found not effective, and 167 were pending.