Lead
On Sept. 5, 2025, researchers reported that a single, high-dose administration of a proprietary LSD formulation (MM120) produced rapid and sustained reductions in symptoms for adults with generalized anxiety disorder (GAD). In a multisite trial of 198 participants across 22 outpatient centers, doses of 100 and 200 micrograms led to measurable improvement by the next day that persisted through a 12-week follow-up; lower doses (25 and 50 micrograms) did not outperform placebo.
Key Takeaways
- Study population: 198 adults diagnosed with generalized anxiety disorder (GAD), recruited at 22 outpatient psychiatric research sites.
- Treatment: single oral dose of MM120 (a proprietary LSD formulation from MindMed) at 25, 50, 100 or 200 micrograms, compared with placebo.
- Primary result: 100 and 200 mcg doses produced rapid anxiety reduction by day two and effects persisted up to 12 weeks.
- Lower doses (25–50 mcg) showed no benefit versus placebo.
- Higher doses also showed greater reductions in co-occurring depressive symptoms.
- Researchers reported good tolerability and safety in the trial population.
- Questions remain about the contribution of setting, music and monitoring to outcomes.
Verified Facts
The trial tested MM120, a branded form of lysergic acid diethylamide (LSD) developed by MindMed, and the results were published in the Journal of the American Medical Association. Investigators enrolled 198 adults diagnosed with GAD—an anxiety disorder that the researchers note affects about one in 10 people in a given year—and randomized them to receive placebo or one of four dose levels.
Participants who received 100 or 200 micrograms experienced pronounced clinical improvement quickly: many showed measurable symptom reduction by the following day. Those improvements were maintained across the 12-week observation period described in the report. By contrast, 25- and 50-microgram arms did not show benefit over placebo.
Site staff conducted dosing sessions in private, “aesthetically pleasant” rooms; two session monitors supervised each session and participants were offered standardized music and eyeshades. Investigators described the drug as generally well tolerated; the report did not identify persistent safety concerns within the 12-week window.
Context & Impact
The study is part of a wave of larger, industry-supported psychedelic trials intended to meet regulatory standards for approval. The U.S. Food and Drug Administration has granted MM120 breakthrough therapy designation, which can accelerate review of promising treatments. MindMed has already launched two phase 3 trials and expects to complete them in 2026.
If replicated and approved, an effective, single-dose psychedelic option could expand treatment choices for people with GAD—particularly those who do not respond to conventional antidepressants or anti-anxiety medications. However, clinicians and researchers caution that non-drug factors—preparation, the therapy setting, music, and practitioner support—may play important roles in outcomes and must be standardized for widespread clinical use.
Potential implications
- Could shorten treatment courses relative to daily medications.
- May require dedicated clinical settings and trained monitors for safe delivery.
- Regulatory approval would hinge on larger phase 3 outcomes and safety data beyond 12 weeks.
Official Statements
“By the next day, they were showing strong improvements,” said Dr. David Feifel about patients receiving higher doses.
Kadima Neuropsychiatry Institute / Dr. David Feifel
“The safety looks good, the tolerability looks good, but where is the depth of information about the way you delivered this product?”
Robin Carhart-Harris, University of California, San Francisco
Explainer: Key terms and procedure
Unconfirmed or Unresolved Points
- The specific influence of music, room design and monitor behavior on outcomes was not fully specified and may have varied across the 22 centers.
- Longer-term durability beyond the 12-week follow-up remains unreported.
- How results generalize to broader clinical populations or real-world settings is not yet established.
Bottom Line
This multisite study shows that a single, sufficiently high dose of a proprietary LSD formulation (MM120) produced rapid and sustained reductions in anxiety and depressive symptoms in people with GAD over a 12-week period. The findings add weight to a growing body of research on psychedelics as psychiatric treatments, but questions about non-drug contributors, long-term safety and wider applicability remain and will be addressed in ongoing phase 3 trials.