Why did the FDA turn down MDMA-assisted therapy for PTSD in 2024?

The FDA turned down MDMA-assisted therapy for PTSD in August 2024 because it judged that the data submitted did not show enough: it cited insufficient data and concerns about trial methodology, and asked for an additional late-stage trial. Developers and supporters disagreed, arguing that most of the requests could be met with existing data.

The background is a drug with a long, odd history. MDMA was first made in 1912 by a chemist at the company Merck, was used to enhance psychotherapy from the 1970s, and became a street drug in the 1980s. It acts mainly by increasing the release of serotonin, dopamine and norepinephrine. When the US Drug Enforcement Administration proposed controlling it in the 1980s, psychiatrists, psychotherapists and researchers objected and asked for a hearing, which surprised the agency; the judge recommended a lighter category, but the DEA administrator overruled and classified it as Schedule I.

The comeback started in 2017, when the FDA gave MDMA-assisted psychotherapy for PTSD breakthrough therapy designation. In December 2023 the developer completed phase 3 trials and filed an application. In the two phase 3 studies, remission rates were 67 to 71% with MDMA-assisted therapy versus 32 to 48% with placebo-assisted therapy.

Then, in June 2024, an 11-member advisory panel voted 9 to 2 that the data did not show effectiveness and 10 to 1 that benefits did not outweigh risks. The reasons cited included concerns about functional unblinding (people can tell that they took MDMA), side effects such as cardiovascular effects, missing detail on misuse potential, and accusations of professional bias. The FDA followed in August 2024. As of August 2026 the company, now renamed Resilient Pharmaceuticals, had resubmitted its application with new data.