08/10/2026
For decades, Americans have trusted the words “FDA approved.” But before 1962, federal approval did not require the modern proof that a new drug actually worked.
That changed after one of the most important episodes in American medical history. FDA reviewer Frances Oldham Kelsey refused to approve thalidomide, marketed as Kevadon, because its safety evidence was inadequate. Overseas, thalidomide became linked to devastating birth defects. Meanwhile, Senator Estes Kefauver had already been investigating the pharmaceutical industry, drug promotion, prices, and medical evidence.
On October 10, 1962, President John F. Kennedy signed the Drug Amendments of 1962. The new law required drug companies to provide evidence of effectiveness as well as safety. Then came the extraordinary part. The FDA and National Academy of Sciences began looking backward at medicines approved under the older system. More than 3,400 drugs entered the retrospective review that became known as DESI.
This is the forgotten story of Frances Oldham Kelsey, Estes Kefauver, John F. Kennedy, thalidomide, the Kefauver-Harris reforms, FDA history, Big Pharma history, and the moment the meaning of “FDA approved” changed in America.