Single microdoses of LSD were felt at higher doses, but mood, thinking and the body barely moved
20 healthy young adults each took placebo, 6.5, 13 and 26 micrograms of LSD a week apart. Effects were felt in step with dose. At 26 micrograms vigor rose slightly; other mood, cognitive and physical measures did not change.
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: Single doses in 20 healthy volunteers; built to pick a dose, not to test a benefit.
The laboratory study that set the dose most later microdosing trials used.
Significant findings
Bershad and colleagues (Biological Psychiatry, 2019) gave 20 healthy young adults four sessions a week apart, in random order and double-blind: placebo, 6.5, 13 and 26 micrograms of LSD. At expected peak effect they completed mood questionnaires and tasks on emotion processing and cognition, and had cardiovascular measures and body temperature taken.
"LSD produced dose-related subjective effects across the 3 doses (6.5, 13, and 26 μg). At the highest dose, the drug also increased ratings of vigor and slightly decreased positivity ratings of images with positive emotional content. Other mood measures, cognition, and physiological measures were unaffected." The authors concluded that a threshold dose of 13 micrograms "might be used safely in an investigation of repeated administrations."
The other direction
This was a first step on purpose: single doses, not the repeated schedule people use, so it cannot speak to cumulative effects for good or ill. The participants were healthy, and the authors say plainly that "It remains to be determined whether the drug improves mood or cognition in individuals with symptoms of depression." The small decrease in positive ratings at 26 micrograms points away from a mood benefit, not towards it.
What this does not show
It does not show any treatment effect, and 20 people cannot detect rare harms. LSD is not approved for any use.
Worth asking
When a product says it is "sub-perceptual", how was that dose measured?
Source
Acute Subjective and Behavioral Effects of Microdoses of Lysergic Acid Diethylamide in Healthy Human Volunteers — Bershad AK, Schepers ST, Bremmer MP, Lee R, de Wit H (2019)
Reputable peer-reviewed journal
Read the source: https://doi.org/10.1016/j.biopsych.2019.05.019
DOI: 10.1016/j.biopsych.2019.05.019
How this was scored
- Study design
- Randomised controlled trial
- Funding
- Independently funded
- Published in
- Reputable peer-reviewed journal
- Sample size
- 20
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published October 21, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 67 out of 100 on our published rubric. One caveat travels with that badge: Single doses in 20 healthy volunteers; built to pick a dose, not to test a benefit. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
Acute Subjective and Behavioral Effects of Microdoses of Lysergic Acid Diethylamide in Healthy Human Volunteers — Bershad AK, Schepers ST, Bremmer MP, Lee R, de Wit H (2019). Published in: Reputable peer-reviewed journal. DOI: 10.1016/j.biopsych.2019.05.019. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Randomised controlled trial. Funding: Independently funded. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.