OPEN Foundation

N. Manson

A low dose of lysergic acid diethylamide decreases pain perception in healthy volunteers


Background: Lysergic acid diethylamide (LSD) is an ergot alkaloid derivative with psychedelic properties that has been implicated in the management of persistent pain. Clinical studies in the 1960s and 1970s have demonstrated profound analgesic effects of full doses of LSD in terminally ill patients, but this line of research evaporated after LSD was scheduled worldwide.

Aim: The present clinical study is the first to revisit the potential of LSD as an analgesic, and at dose levels which are not expected to produce profound mind-altering effects.

Methods: Twenty-four healthy volunteers received single doses of 5, 10 and 20 µg LSD as well as placebo on separate occasions. A Cold Pressor Test was administered at 1.5 and 5 h after treatment administration to assess pain tolerance to experimentally evoked pain. Ratings of dissociation and psychiatric symptoms as well as assessments of vital signs were included to monitor mental status as well as safety during treatments.

Results: LSD 20 µg significantly increased the time that participants were able to tolerate exposure to cold (3°C) water and decreased their subjective levels of experienced pain and unpleasantness. LSD elevated mean blood pressure within the normal range and slightly increased ratings of dissociation, anxiety and somatization.

Conclusion: The present study provides evidence of a protracted analgesic effect of LSD at a dose that is low enough to avoid a psychedelic experience. The present data warrant further research into the analgesic effects of low doses of LSD in patient populations.

Ramaekers, J. G., Hutten, N., Mason, N. L., Dolder, P., Theunissen, E. L., Holze, F., … & Kuypers, K. P. (2020). A low dose of lysergic acid diethylamide decreases pain perception in healthy volunteers. Journal of Psychopharmacology, 0269881120940937; 10.1177/0269881120940937
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Motives and side-effects of microdosing with psychedelics among users



Microdosing with psychedelics has gained considerable media attention where it is portrayed as a performance enhancer, especially popular on the work floor. While reports are in general positive, scientific evidence about potential negative effects is lacking aside from the prevalence and motives for use. The present study addressed this gap by surveying psychedelic users about their experience with microdosing including their dosing schedule, motivation, and potential experienced negative effects.


An online questionnaire was launched on several websites and fora between March and July 2018. Respondents who had consented, were 18 years of age or older, and had experience with microdosing were included in the analyses.


In total, 1116 of the respondents were either currently microdosing (79.5%) or microdosed in the past (20.5%). Lysergic acid diethylamide (10 mcg) and psilocybin (0.5 g) were the most commonly used psychedelics with a microdosing frequency between 2 and 4 times per week. The majority of users, however, were oblivious about the consumed dose. Performance enhancement was the main motive to microdose (37%). The most reported negative effects were of psychological nature and occurred acutely while under the influence.


In line with media reports and anecdotes, the majority of our respondents microdosed to enhance performance. Negative effects occurred mostly acutely after substance consumption. However, the main reason to have stopped microdosing was that it was not effective. Future experimental placebo-controlled studies are needed to test whether performance enhancement can be quantified and to assess potential negative effects after longer term microdosing.

Hutten, N. R., Mason, N. L., Dolder, P. C., & Kuypers, K. P. (2019). Motives and side-effects of microdosing with psychedelics among users. International Journal of Neuropsychopharmacology., 10.1093/ijnp/pyz029

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