THEPSYCHEDELICLIBRARY

Molecule guide

LSD: what the research shows

One of the first psychedelics studied in medicine, now in late-stage trials for anxiety. How LSD works and how strong the evidence is.

ReviewedLast updated September 25, 2026

Also known as Lysergic acid diethylamide, Lysergide, MM120

At a glance

Type
Classic psychedelic (an ergoline). Active at extremely small doses, measured in micrograms.
How it acts
Activates serotonin 2A receptors, the main target of classic psychedelics.
Approved uses
None. A pharmaceutical form (MM120) has FDA Breakthrough Therapy designation for generalized anxiety disorder.
Legal status
Schedule III in Canada. Schedule I in the US.
How it's given in research
One or two supervised oral doses. Effects last many hours, much longer than psilocybin.
Strongest evidence
Generalized anxiety disorder, from a 198-person randomised trial.
Biggest open question
Whether phase 3 trials confirm the anxiety results, and how the long session length fits into real-world care.

Evidence by condition

How strong the research is for each use, on our four-level evidence scale.

Generalized anxiety disorder Moderate

A 198-person phase 2b randomised trial found a single dose reduced anxiety in a dose-dependent way, with the higher doses beating placebo. Phase 3 trials are under way.

Anxiety with or without life-threatening illness Low

Two small randomised crossover trials (42 and 12 people) found lasting reductions in anxiety, up to 16 weeks and 12 months respectively.

Alcohol use disorder Low

A meta-analysis of six trials from the 1960s and 1970s (536 people) found better outcomes with a single LSD dose. The trials used older methods and haven't been repeated with modern designs.

What it is

LSD was first made in 1938 by the Swiss chemist Albert Hofmann at Sandoz, while working with compounds from ergot, a fungus that grows on grain. He discovered its effects in 1943.6 Through the 1950s and 1960s, it was studied widely in psychiatry, including for alcoholism, before research largely stopped when psychedelics were banned around 1970.6

Modern research restarted in Switzerland in the 2010s. Today a pharmaceutical form of LSD, called MM120, is in phase 3 trials.

How it works in the brain

Like psilocybin, LSD activates the serotonin 2A receptor.6 It’s extraordinarily potent: active doses are measured in micrograms (millionths of a gram). Its effects last much longer than psilocybin’s, so trials involve long, supervised dosing days.

Key studies

Generalized anxiety disorder, 2025. In a phase 2b trial at 22 US sites, 198 adults with moderate to severe generalized anxiety disorder received a single dose of MM120 at one of four strengths, or a placebo. There was no added psychotherapy, just monitoring on the dosing day.5 At four weeks, the two higher doses reduced anxiety significantly more than placebo, while the two lower doses did not. The most common side effects were visual changes on the dosing day.1

Anxiety, with or without serious illness, 2023. In a Swiss randomised crossover trial with 42 participants, two LSD sessions reduced anxiety and depression scores up to 16 weeks later. Mild side effects on the dosing day were reported by 19% of participants.2 An earlier pilot of 12 people with life-threatening illness found reductions in anxiety that lasted 12 months.3

Alcoholism, historical trials. A 2012 meta-analysis pooled six randomised trials from the 1960s and 1970s, with 536 participants. It found that a single LSD dose roughly doubled the odds of improvement in alcohol misuse.4

Safety and risks reported in research

In modern trials, side effects were mostly limited to the dosing day. In the 2025 anxiety trial, the most common were visual changes, headache and nausea.1 In the 2023 Swiss trial, 19% of participants reported mild, short-lived side effects.2

  • Canada: Schedule III under the Controlled Drugs and Substances Act.8 The Special Access Program exemption covers only psilocybin and MDMA, so LSD is available only in approved research.9
  • United States: Schedule I. MM120 has FDA Breakthrough Therapy designation for generalized anxiety disorder, which speeds up review but is not an approval.5

History in brief

  • 1938: First made by Albert Hofmann at Sandoz.6
  • 1943: Hofmann discovers its effects.6
  • 1950s–1960s: Widely studied in psychiatry, including for alcoholism.4
  • Around 1970: Research largely stops as psychedelics are banned.6
  • 2014: First modern controlled LSD therapy study published.3
  • 2023: Swiss randomised trial in anxiety published.2
  • 2024: FDA grants MM120 Breakthrough Therapy designation for generalized anxiety disorder.5
  • 2025: Phase 2b anxiety trial published in JAMA. Phase 3 trials under way.1

Myths vs evidence

The claim“LSD research is a relic of the 1960s.”

What the evidence says False

A 198-person randomised trial of LSD for generalized anxiety disorder was published in JAMA in 2025.1 It received FDA Breakthrough Therapy designation in 2024, and phase 3 trials are under way.5

The claim“One dose of LSD will make you permanently lose your mind.”

What the evidence says Misleading

In modern trials with screened participants, side effects were mostly short-lived and limited to the dosing day.2 The real psychological risks, such as frightening experiences and possible lasting problems in people prone to psychosis, are why trials screen and supervise carefully.7

See all myths vs evidence →

Frequently asked questions

How is LSD different from psilocybin?

Both are classic psychedelics that act on serotonin 2A receptors, and their effects are broadly similar. LSD is active at much smaller doses, micrograms rather than milligrams, and its effects last considerably longer.

What is MM120?

MM120 is a pharmaceutical form of LSD (lysergide) developed for clinical trials. It's the version tested in the 2025 anxiety trial and now in phase 3 trials for generalized anxiety disorder and depression.

Does microdosing LSD work?

The trials on this page tested full, supervised doses, not microdoses. Microdosing is a separate question with its own, more limited evidence. We cover it separately.

Is LSD therapy legal in Canada?

No. LSD is a Schedule III controlled substance and isn't currently accessible through Health Canada's Special Access Program, which covers psilocybin and MDMA. It can only be used in approved research. Talk to a qualified health professional about your own situation.

Clinical trials

Showing 8 of 12 active trials in our tracker.

See all trials in the tracker →

References

  1. Robison R, et al. Single treatment with MM120 (lysergide) in generalized anxiety disorder: a randomized clinical trial. JAMA. 2025;334(15):1358–1372. Source
  2. Holze F, et al. Lysergic acid diethylamide-assisted therapy in patients with anxiety with and without a life-threatening illness: a randomized, double-blind, placebo-controlled phase II study. Biological Psychiatry. 2023;93(3):215–223. Source
  3. Gasser P, et al. Safety and efficacy of lysergic acid diethylamide-assisted psychotherapy for anxiety associated with life-threatening diseases. Journal of Nervous and Mental Disease. 2014;202(7):513–520. Source
  4. Krebs TS, Johansen PØ. Lysergic acid diethylamide (LSD) for alcoholism: meta-analysis of randomized controlled trials. Journal of Psychopharmacology. 2012;26(7):994–1002. Source
  5. MindMed. MindMed receives FDA Breakthrough Therapy designation and announces positive 12-week durability data from phase 2b study of MM120 for generalized anxiety disorder. Company announcement, March 7, 2024. Source
  6. Nichols DE. Psychedelics. Pharmacological Reviews. 2016;68(2):264–355. Source
  7. Johnson MW, Richards WA, Griffiths RR. Human hallucinogen research: guidelines for safety. Journal of Psychopharmacology. 2008;22(6):603–620. Source
  8. Government of Canada. Controlled Drugs and Substances Act (S.C. 1996, c. 19), Schedule III. Source
  9. Canada Gazette, Part II. Regulations Amending Certain Regulations Relating to Restricted Drugs (Special Access Program), SOR/2021-271. January 5, 2022. Source