Microdosing is the practice of taking a small amount of a psychedelic substance, most commonly LSD or Psilocybe mushrooms, on a regular basis. These doses are usually between 5 and 10 percent of a standard psychedelic dose, sub-perceptible amounts that don’t impede everyday function. While advocates argue that the practice delivers some of the cognitive and medicinal benefits of full-dose psychedelics, scientific studies on microdosing are inconclusive.

There is anecdotal evidence that microdosing can be effective. Some users have claimed that the practice treats anxiety and improves concentration and creativity. Observational studies, in which scientists survey users who have microdosed on their own, have found that microdosing can also boost creativity and improve mental health.

However, these studies are limited. Observational studies do not allow for comparisons between groups of participants who, under blinded conditions, get the active drug versus those who receive a placebo (the control group). Without effective blinding and a control group, confirmation bias and placebo effects can skew results: because people believe microdosing will help them, they experience improvement.

Double-blind, placebo-controlled trials have shown mixed results. One study found that microdosing with Psilocybe mushrooms did not alleviate the symptoms of anxiety and depression any more than a placebo did. Another found that microdosing with LSD was safe in a controlled setting with limited use, but the changes it caused were negligible.

In another trial, researchers provided study participants with a way to “self-blind” at home, randomizing placebo and active drug through the use of non-transparent capsules and QR codes. The participants provided their own material, usually LSD or Psilocybe mushrooms, which they took by themselves.

The study found that microdosing led to significant improvements in well-being, mindfulness, life satisfaction, and diminishment of paranoia. However, the researchers also found that participants often correctly guessed whether they’d taken the placebo or the active psychedelic substance, essentially unblinding themselves. Therefore, the researchers state that the improvements the participants observed could be attributable to a placebo effect rather than to any tangible changes caused by the psychedelic itself.

The scientific community is still divided about attributing microdosing improvements to the placebo effect. A systematic review of forty-four microdosing studies published between 1955 and 2021 reported changes in pain perception, time perception, conscious state, and neurophysiology, and found that self-reported studies indicated changes in mental health and cognitive processing. The authors of the review argue that it’s premature to claim that expectations predominantly shape the effects of microdosing.

Selected Sources

Psilocybin microdosing does not affect emotion-related symptoms and processing: A preregistered field and lab-based study. Marschall, J., Fejer, G., Lempe, P., Prochazkova, L., Kuchar, M., Hajkova, K., & van Elk, M. Journal of Psychopharmacology, 36(1), 97–113. 2022.

Repeated low doses of LSD in healthy adults: A placebo-controlled, dose–response study. Harriet de Wit, Hanna M. Molla, Anya Bershad, Michael Bremmer, Royce Lee. Addiction Biology 27(2). 2022.

Self-Blinding Citizen Science to Explore Psychedelic Microdosing.” B. Szigeti et al. eLife 10. March 2021.

The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955–2021) and recommendations for the field. Vince Polito, Paul Liknaitzky. Neuroscience and Biobehavioral Reviews, 139. 2022.