This study found that placebos had almost the same effects on users as micro-doses of LSD. In short, the uplift reported by microdosers might be nothing more than the placebo effect.


Balázs Szigeti (email:, Laura Kartner, Allan Blemings, Fernando Rosas, Amanda Feilding, David J Nutt, Robin L. Carhart-Harris, David Erritzoe


Szigeti, B., Kartner, L., Blemings, A., Rosas, F., Feilding, A., Nutt, D., Carhart-Harris, R. and Erritzoe, D., 2021. Self-blinding citizen science to explore psychedelic microdosing. eLife, 10.

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Self-Blinding Citizen Science To Explore Psychedelic Microdosing



Microdosing is the practice of regularly using low doses of psychedelic drugs. Anecdotal reports suggest that microdosing enhances well-being and cognition; however, such accounts are potentially biased by the placebo effect.


This study used a ‘self-blinding’ citizen science initiative, where participants were given online instructions on how to incorporate placebo control into their microdosing routine without clinical supervision. The study was completed by 191 participants, making it the largest placebo-controlled trial on psychedelics to-date.


All psychological outcomes improved significantly from baseline to after the four weeks long dose period for the microdose group; however, the placebo group also improved and no significant between-groups differences were observed. Acute (emotional state, drug intensity, mood, energy, and creativity) and post-acute (anxiety) scales showed small, but significant microdose vs. placebo differences; however, these results can be explained by participants breaking blind.


The findings suggest that anecdotal benefits of microdosing can be explained by the placebo effect.

Research in context

This study found that placebos had almost the same effects on users as micro-doses of LSD. In short, the uplift reported by microdosers might be nothing more than the placebo effect.

The study recruited 191 people who were already microdosing with LSD and able to participate online. The volunteers followed instructions to prepare gel capsules containing either a low dose of LSD, estimated at about 13μg, or a placebo. They then followed instructions to muddle up the capsules in envelopes bearing QR codes so they did not know which they took when.

During the study, the researchers used scans of the QR codes to log when each participant took a placebo versus a microdose of LSD. Throughout the four-week trial, the volunteers completed surveys on how they felt and performed a series of online cognitive tests.

The scientists found that there was no statistically significant difference between the reported improved wellbeing, mindfulness and life satisfaction between the micro-doses and placebos.

The scientists note limitations as the study was not as a standard, laboratory-based placebo-controlled clinical study. However, the results are still valid.

This suggests that the perceived beneficial effects of microdosing psychedelics in this group are more likely to be a result of positive expectation than the capacity of the drug to induce a beneficial effect,” said James Rucker, a clinician scientist who runs the psychedelic trials group at King’s College London, as per Dalgarno Institute.

James Rucker, clinician scientist, the psychedelic trials group at King’s College London

Source Website: eLife