Nearly 70% Of New Drugs Now Win FDA Approval With Just One Study

When a new prescription lands on a pharmacy counter, the assumption is that it went through years of testing, checked and rechecked before ever reaching a shelf. That assumption isn’t as safe as it used to be. A new analysis of every novel drug the Food and Drug Administration approved between 2016 and 2024 found that most reached the market on the strength of a single clinical study, a sharp break from years earlier when the agency typically wanted evidence from three or more trials.

Researchers built a database covering 6,763 studies tied to FDA drug approvals over the nine-year period, publishing their findings in the journal PLOS One. The numbers show an agency relying on fewer studies, leaning more heavily on industry-funded evidence, and operating within a system where results often take years to reach the public. In 2016, 59.1% of approved drugs had backing from three or more trials; by 2024 that figure had fallen to 5.6%, while 69.4% of drugs approved that year made it through on a single study.

None of this points to one drug slipping through the cracks. The trend unfolded during the years following the 21st Century Cures Act, a 2016 law that gave the FDA more flexibility in how much proof it demands...