A big self-blinded study: microdose and placebo groups both improved
In a citizen-science study, 191 people ran their own blinded microdosing experiment, using a placebo they could not identify. Most took LSD, and fewer took psilocybin mushrooms. Over four weeks, both the microdose and placebo groups improved on several measures, and there were no significant differences between them.
Worth knowing
Participants set up the protocol themselves and chose their own amounts, and nobody verified what the capsules contained. Microdosers were a self-selected group with optimistic expectations, and well-being rose only in the microdose group, though the difference between groups was not significant. It shows that expectation matters a great deal. It does not show that microdosing does nothing.