Microdosing's Feel-Good Benefits Might Just Be Placebo Effect

In 2018, volunteers with an interest in microdosing—regularly taking tiny amounts of psychedelic drugs such as LSD—began taking part in an unusual experiment. For four weeks, researchers at Imperial College London asked them to swap some of their drugs with empty capsules—placebos—so that when they took them, they didn’t know if they were microdosing or not. They then completed online surveys and cognitive tasks at regular intervals, aimed at gauging their mental well-being and cognitive abilities. The idea: to explore if microdosing produces the benefits to mood and brain function that some people claim.

In a paper published in the journal eLife, the researchers revealed their findings. After the month-long testing period, they found that all psychological outcomes had improved since the start of the experiment for those in the microdosing group, including “in the domains of well-being, mindfulness, life satisfaction, and paranoia.” However, the same was true for the placebo group—with no significant differences between the two.

“So, in a way, microdosing did increase a lot of these psychological variables,” says Balazs Szigeti, a research associate at Imperial College London Centre of Psychedelic Research and the lead author of the study. “But so did taking placebos for four weeks.”The researchers conclude that the anecdotal benefits of microdosing can therefore be explained by the placebo effect. That’s not to say that people who claim to feel benefits from microdosing are wrong, Szigeti says—on the contrary, the study suggests that they do feel these benefits—but that these outcomes may not be the result of the pharmacological effect of the drug but instead due to their psychological expectations.

People who microdose take very small amounts of psychedelic drugs such as LSD or psilocybin (found in magic mushrooms)—usually around a tenth of the amount you’d take to get a full psychedelic experience. Some people claim that microdosing has mood-enhancing effects, while others claim cognitive benefits or say it makes them feel more creative or effective at work. Others microdose in an attempt to self-medicate conditions such as depression. But there is very little scientific evidence on the effects of microdosing, and it is difficult to run controlled trials (not least because of the illegal nature of these drugs in many countries.)

The Imperial team turned to volunteers who planned to microdose independently, and asked them to complete the surveys and cognitive tasks at specific times during their microdosing schedule. The volunteers never came into the lab, and the researchers did not provide the drugs. In order to “self-blind” so that they didn’t know whether they were taking a microdose or placebo, volunteers were instructed to put their microdoses into opaque pill capsules and then put a week’s worth of capsules into an envelope with a QR code. They then mixed these up so that some of the envelopes contained microdoses and others contained placebos. Some people would take only microdoses for four weeks, others only placebos, and some half-half. After the study, the QR codes acted as a key to determine which were which.

While the study also measured effects a few hours after taking a microdose, and on a weekly basis, it was the monthly accumulative effect that showed most interesting results. A week after the dosing period had ended, participants were asked to report on psychological measures relating to well-being, mindfulness, life-satisfaction, and paranoia. For both the microdosing group and the placebo group, these showed overall improvement compared to a baseline taken before the start of the study, with no significant difference between the two groups. Overall, cognitive measures—which are less subjective—showed no significant improvement for either group. “So people are cognitively performing at the same level before and after these four weeks long dose period,” Szigeti says.