Thalidomide Scandal Drives Kefauver-Harris Amendment Strengthening FDA Drug Safety Requirements

On October 10, 1962, President John F. Kennedy signed the Kefauver-Harris Amendment to the Federal Food, Drug, and Cosmetic Act, fundamentally transforming pharmaceutical regulation in the United States. The legislation, driven by the thalidomide disaster in Europe, required drug manufacturers to prove both safety and efficacy before FDA approval, mandated informed consent from patients in clinical trials, and established Good Manufacturing Practice requirements.

Thalidomide, a sedative marketed in Europe and Canada as safe for pregnant women, caused devastating birth defects in over 10,000 children worldwide, including shortened or absent limbs. The drug had been approved in 46 countries, but FDA medical reviewer Dr. Frances Kelsey had refused to approve it for the American market despite intense pressure from Richardson-Merrell, the company seeking approval. Kelsey demanded additional safety data, particularly regarding the drug’s effects on peripheral nerves, delaying approval until reports of birth defects emerged from Europe.

Senator Estes Kefauver of Tennessee had been investigating pharmaceutical industry practices since 1959, documenting price-gouging, ineffective drugs, and misleading advertising. The pharmaceutical industry had successfully stalled his reform legislation for years through intensive lobbying. The thalidomide scandal broke the industry’s resistance; the near-miss of a national tragedy created irresistible public pressure for reform.

The pharmaceutical industry lobbied to weaken the bill even as public outrage mounted. Companies successfully removed provisions requiring generic drug names to be as prominent as brand names and defeated proposals for government price controls. Nevertheless, the final legislation significantly expanded FDA authority.

The amendment required manufacturers to prove drug efficacy through “adequate and well-controlled investigations”—clinical trials—before approval. It mandated disclosure of side effects in advertising, required informed consent from clinical trial participants, and established FDA oversight of drug manufacturing. President Kennedy awarded Dr. Kelsey the President’s Award for Distinguished Federal Civilian Service, the highest honor for government employees, in August 1962.

The Kefauver-Harris Amendment demonstrated how public health crises could overcome entrenched industry opposition to regulation. It also illustrated industry’s capacity to shape legislation even in moments of crisis, successfully removing the strongest provisions from reform bills. The framework established in 1962 remains the foundation of FDA drug regulation, though subsequent decades would see continued industry efforts to weaken oversight.