LSD microdosing

What LSD microdosing is and how it is supposed to work

LSD binds mainly to the serotonin receptor 5-HT2A in the cerebral cortex. At a full dose, this alters perception and thinking for hours. With microdosing, an amount below this threshold is supposed to lift mood and thinking over days without any unusual experience.

That even very small amounts trigger something has been measured: in a double-blind laboratory study, healthy people felt dose-dependent effects. A path from this mild acute effect to a lasting improvement, by contrast, has not been shown in humans. You can find most of the data on high-dose psychedelics on the page on psilocybin.

What the studies show

Szigeti 2021: the self-blinding study

191 people who were already microdosing followed instructions to mix their own capsules with empty ones, without knowing which they were taking. After 4 weeks, all psychological scores had improved, but just as much in the placebo group. Small differences on dosing days could be explained by participants recognizing what they had taken. The study covered LSD and psilocybin.

Bershad 2019: single doses in the lab

20 young healthy people received, double-blind, placebo or one of three low amounts in four sessions. They felt something in a dose-dependent manner; at the highest level, vigor increased, and positive images seemed somewhat less positive. Other mood measures, cognition, pulse and blood pressure remained unchanged.

Murphy 2023 and 2025: six weeks at home

80 healthy men received LSD or placebo repeatedly over 6 weeks, taking most doses at home. On dosing days, creativity, connectedness, energy, happiness and well-being were higher, as was irritability. Between baseline and week 6, however, no questionnaire and no cognitive test changed. In the 2025 analysis, four different creativity tests found no difference either acutely or after 6 weeks, even though the participants felt more creative.

MindMed ADHD study: primary endpoint missed

The manufacturer, now Definium Therapeutics, tested low-dose LSD in 53 adults with ADHD over 6 weeks, triple-blind. The ADHD scale fell almost equally in both groups, from 37.4 to 29.6 on LSD and from 37.3 to 29.0 on placebo. No difference.

Daldegan-Bueno 2026: open study in depression

19 people with depression repeatedly took small amounts of LSD over 8 weeks and reported on average 60 percent fewer symptoms. There was no control group. On dosing days mood was better, but the daily depression score was not. The authors themselves call for controlled confirmation.

Where the data stop — and where they point the other way

For the core of the promise, lastingly better mood, more creativity and focus, the controlled data point the other way. What remains is a mild effect on the dosing day that participants feel and that is therefore hard to separate from expectation. The studies are small, ran for 8 weeks at most and were mostly in healthy people. Whether people with depression respond differently is open; the only study on this had no control group.

Not to be confused: the positive studies by the manufacturer Definium (formerly MindMed) on generalized anxiety disorder test a single full dose with a high, not microdosing. In the phase 2b trial with 198 adults, only the two higher of four dose levels worked; the two lowest did not differ from placebo.

Status, approval and legal

In Germany, lysergide, that is LSD, is listed in Annex I of the German Narcotics Act: not marketable and not prescribable; even possession is a criminal offense. There is no approved LSD product in either the EU or the US, and no approval procedure is underway for microdosing.

Furthest along is an LSD orally disintegrating tablet from Definium Therapeutics (MM120, now DT120) for generalized anxiety disorder, as a single full dose. According to the manufacturer, two phase 3 trials were positive in 2026; in Panorama, with 245 participants, there was a 5.1-point difference on the anxiety scale after 12 weeks. These figures are so far available only as a press release; a US approval application is planned for the first half of 2027.

Safety

In the controlled studies, the most common notable side effect was anxiety: 4 of 40 men in the LSD group discontinued because of it. In the ADHD study, no serious events occurred in either group. All of these studies, however, ran for 8 weeks at most.

The question of the heart is open. LSD also activates the serotonin receptor 5-HT2B, through which other drugs have damaged heart valves with long-term use. A 2023 review considers the safety margins with microdosing to be larger than with these drugs, but not risk-free, and found not a single study that had examined this appropriately in humans. Outside of studies, unknown content and the criminal-law side come on top.

Sources

• Szigeti B et al., eLife 2021 – self-blinding microdosing study (LSD and psilocybin), 191 participants
• Murphy RJ et al., Biol Psychiatry 2023 – randomized LSD microdosing study at home, 80 healthy men
• Murphy RJ et al., Psychopharmacology 2025 – creativity tests after acute and six-week LSD microdosing
• Bershad AK et al., Biol Psychiatry 2019 – acute effects of low LSD amounts, double-blind, 20 healthy people
• ClinicalTrials.gov NCT05200936 – low-dose MM120 in ADHD, phase 2a, 53 adults, results
• Daldegan-Bueno D et al., Prog Neuropsychopharmacol Biol Psychiatry 2026 – open phase 2a study of LSD microdosing in depression, 19 participants
• Robison R et al., JAMA 2025 – MM120 (lysergide) as a single dose in generalized anxiety disorder, phase 2b, 198 adults
• Definium Therapeutics, press release of September 14, 2026 on the phase 3 trial Panorama (245 participants)
• Tagen M et al., J Psychopharmacol 2023 – heart valve risk with chronic microdosing
• German Narcotics Act, Annex I (lysergide)