LSD-Derived MM120 Reduced Anxiety in a Phase 2b Study

A phase 2b trial published in JAMA in 2025 found that an investigational formulation of lysergide, commonly known as LSD, reduced anxiety symptoms in adults with generalized anxiety disorder. The findings support further testing, not self-treatment or an assumption that ordinary LSD products provide an established medical therapy.

What researchers tested

The trial enrolled 198 adults at 22 outpatient psychiatric research sites in the United States. Participants had moderate to severe generalized anxiety disorder and were randomized among four MM120 treatment groups and placebo. Independent central raters assessed symptoms without knowing treatment assignment or the study visit date.

The primary analysis examined the relationship between treatment level and change on the Hamilton Anxiety Rating Scale at four weeks. The two higher treatment groups showed statistically significant improvement compared with placebo; the two lower groups did not. Among 194 participants in the full analysis set, the higher groups' placebo-adjusted differences were approximately five and six points.

Why that finding is interesting

Generalized anxiety disorder can involve persistent worry, tension, sleep problems, and impaired functioning. Existing treatments do not help everyone sufficiently. A controlled signal from a new intervention is therefore clinically relevant, particularly when measured beyond the day of administration.

However, a symptom-scale difference is not identical to restored functioning, permanent recovery, or a favorable long-term benefit-risk balance. The principal endpoint was at four weeks. Additional follow-up can add context, but it cannot establish how well a treatment will work over years or with repeated use.

Side effects were noticeable

Visual perceptual changes were common, especially in the higher treatment groups. Nausea and headache were also reported. Calling these effects expected does not make them unimportant: they affect patient experience, supervision needs, and the practicality of delivering treatment outside a trial.

Those noticeable effects also complicate masking. Even when independent raters remain unaware of assignment, participants may recognize that they received a psychoactive treatment. Expectations and interactions during the study can then influence outcomes in ways that central assessment does not completely remove.

What remains uncertain?

About 83% of the analysis population was White, limiting confidence about how well results generalize across more diverse populations. The study also involved sponsor-affiliated authors. Financial relationships should be disclosed and considered alongside the methods, without treating affiliation alone as proof that results are unreliable.

Phase 2b findings help guide subsequent development, including treatment selection for larger studies. They do not by themselves establish regulatory approval. This report does not infer or announce any later phase 3 outcome. In the United States, research authorization and FDA marketing approval are distinct. Patients with anxiety should discuss established treatments and legitimate research opportunities with a clinician rather than extrapolate trial results to unsupervised LSD use or commercially advertised microdosing.

Sources

• JAMA: MM120 randomized trial in generalized anxiety disorder
• Full report, methods, and conflict disclosures
• FDA: Psychedelic drug investigation guidance