The problem is, there's very little research on microdosing, even though the topic has really gained traction among users, says David Nichols, PhD, co-founder and chairman of the board for the The Heffter Research Institute, an organisation that promotes research of hallucinogens. There has yet to be a randomised placebo-controlled clinical trial, which is the gold standard for assessing a drug's effects, on the effects of microdosing psilocybin. "My opinion is that a lot of folks who claim benefit from microdosing actually are experiencing the placebo effect; they believe it is doing something," he adds. Dr. De Wit adds that the alleged beneficial effects of microdosing are "confounded by peoples' strong expectations that what they take will make them feel better, and there is a need for double-blind controlled studies." Considering how small a microdose typically is, the effects could potentially be placebo, agrees Dr. Garcia-Romeu.