An estimated 10 million American adults microdosed psilocybin, LSD, or MDMA in 2025, a new report on nationwide psychedelics use showed.

Psilocybin was the most used psychedelic substance, followed by MDMA and the mushroom Amanita muscaria, in the 2025 Psychedelics Survey conducted by RAND, a nonprofit think tank based in Santa Monica, California.

Of a total 216 million days of psilocybin use in the past year, 47% involved microdosing. The analysis also showed 62.5 million use days for MDMA and 21 million use days for LSD, with microdosing accounting for 42% and 41%, respectively. 

“We were surprised about the number of people that are microdosing, especially for MDMA. There's a lot of discussion around psilocybin and LSD, but we were surprised to see the numbers for MDMA similarly high to the other two substances,” lead author Michelle Priest, PhD, and research project specialist at RAND, told Medscape Medical News. 

Growing Public Interest

The FDA has granted breakthrough therapy status to a number of novel compounds based on psilocybin, LSD, and MDMA for the treatment of a range of psychiatric conditions, although trials are ongoing.

Definitions of psychedelic microdosing vary, but it typically involves taking a small amount of a psychedelic substance — usually one fifth to one twentieth of a recreational dose — with the goal of improving cognition or psychological mood while minimizing hallucinogenic effects. 

Evidence of benefit from microdosing is mixed, with some early reports showing positive effects for mental health and well-being and other studies showing no benefit compared to placebo. 

Despite scant evidence of efficacy or safety, public interest in microdosing psychedelics is growing, with users on social media reporting effects ranging from improved creativity to reduced anxiety and depression. 

The latest National Survey on Drug Use and Health reported that 10.4 million people used hallucinogens in 2024, but these surveys don’t include specifics about microdosing. Previous global reports estimated that 1 in 4 people who used LSD or psilocybin did so by microdosing. 

The RAND study is a probability-based, nationally representative survey of 10,122 adults that provides sample coverage of around 97% of all US households.

Participants were questioned about their lifetime and past-year use of 11 psychedelic substances, including psilocybin, MDMA, Amanita muscaria, ketamine, LSD, DMT, mescaline, 2C-B, Salvia divinorum, ibogaine, and 5-MeO-DMT. 

A broad definition of psychedelics was used to capture as much information as possible on people’s usage, Priest said.

For the study, microdosing was defined as taking a subperceptual dose of a psychedelic substance that is much lower than the amount needed to “trip” or hallucinate.

Small Doses, 'Big Deal'

The unweighted number of participants who reported past-year use for psilocybin was 372, for MDMA was 163, and for LSD was 90. Population estimates were weighted to reflect the US adult population.

On the basis of those calculations, in 2025, an estimated 11 million adults used psilocybin, 4.7 million used MDMA, and 3.5 million used Amanita muscaria mushrooms. Ketamine and LSD also ranked in the top five most used substances. 

Among those who reported past-year use, an estimated 69% microdosed psilocybin, 65% MDMA, and 59% LSD at least once.

The investigators estimated 216 million use days for psilocybin, 62.5 million use days for MDMA, and 21 million use days for LSD, with roughly half of the use days involving microdosing for each substance.

Approximately 3.7% of the US adult population microdosed psilocybin, MDMA, or LSD.

“There is an emerging discussion about the effects of microdosing on creativity, well-being, and mental health, but until now little was known about how common it is,” Priest said in a statement. “Our findings suggest that for those who use psychedelics, taking small doses is a big deal.”

Trend Moving Faster Than the Evidence?

Commenting on the survey results for Medscape Medical News, Gerald Busch, MD, a psychiatrist based in Hawaii and member of the American Psychiatric Association’s Council on Addiction Psychiatry, called the number of people microdosing “astounding.” 

“What I feel the study shows is that [psychedelics] are not a niche drug anymore. They’re like a mainstream public health issue,” said Busch, who was not involved in the study. “For microdosing, it's almost like the policy or the things people believe are moving faster than the evidence.” 

Many psychedelics are illegal at the federal level, although some states, such as Colorado and Oregon, have decriminalized or legalized psilocybin for certain uses.

However, Amanita muscaria, one of the most used psychedelics in the survey, is not listed on the federal Controlled Substances Act, which Priest said can make it easier to legally access this substance.

“The big problem is that it’s perceived as legal or natural, but it carries a different and much less predictable risk profile than all the other psychedelics,” Busch added.

Experts have called for more decisive regulation and for mental health professionals to outline the differences between psilocybin and Amanita muscaria, which can be more toxic and has no clinical evidence supporting its use.

Microdosing Not Without Risk

Commenting on the results for Medscape Medical News, Greg Fonzo, PhD, assistant professor and co-director at the Center for Psychedelic Research and Therapy at The University of Texas Dell Medical School in Austin, said he was less surprised by the survey’s numbers, remarking that microdosing seems to be a “fashionable trend.”

Part of the appeal are the potential benefits of psychedelics for mental illness without the full psychedelic experience, said Fonzo, who was not involved in the study and is currently researching psilocybin for treatment-resistant depression in conjunction with noninvasive brain stimulation.

However, microdosing is not without risk, Fonzo said. 

“Even at low doses, we don't know what the long-term effects could be, especially if it's taken chronically,” he said.

Limitations of the survey were its cross-sectional design, self-reported data, and the lack of a universal definition of a microdose. 

The survey was supported by DAFgiving360. Priest and Busch reported no relevant disclosures. Fonzo reported involvement in two ongoing commercial psychedelic trials for Compass Pathways and Definium Therapeutics.