Key takeaways:
- Cannabis is the most commonly microdosed substance in the U.S., with about 9.4% of adults — roughly 24 million people — reporting lifetime use. More people reported microdosing for recreational reasons than for medical reasons.
- Cannabis microdosing was nearly twice as common as psilocybin, LSD or MDMA, challenging the perception that microdosing is mainly a psychedelic practice.
- Microdosing was more common among people reporting poorer mental health.
Researchers from University of California San Diego have found that microdosing — taking very small amounts of psychoactive substances — is more common among U.S. adults than previously recognized, with cannabis leading by a wide margin. The study, published May 4, 2026 in the American Journal of Preventive Medicine, estimates that millions of Americans have microdosed substances such as cannabis, psilocybin, LSD ("acid") and MDMA ("ecstasy").
"Microdosing is often discussed in the context of psychedelics like psilocybin or LSD, but what surprised us most was that cannabis microdosing was almost twice as common," said Kevin Yang, MD, resident physician in the Department of Psychiatry at UC San Diego School of Medicine and first author of the study. "That suggests conversations about microdosing may be overlooking a large group of people who are using small amounts of cannabis in similar ways."
"Most proponents of microdosing recommend use under specific protocols that involve taking low doses of LSD or psilocybin for specific health applications," said Eric Leas, PhD, MPH, assistant professor at the UC San Diego Herbert Wertheim School of Public Health and Human Longevity Science and senior author of the study. "That's not what we found. Most people are microdosing for recreational purposes. That suggests that many people could think about the concept of 'microdosing' more as a way of lowering dosage. They may just want to take less, so they don't want to get as high."
Microdosing typically involves consuming about one-fifth to one-twentieth of a typical recreational dose, with the goal of avoiding strong psychoactive effects while potentially experiencing subtler benefits such as improved mood, reduced anxiety or enhanced creativity.
To better understand how common the practice is, researchers analyzed data from a nationally representative survey of 1,525 U.S. adults conducted in late 2023 through the Ipsos KnowledgePanel, which uses probability-based sampling to reflect the U.S. population. Participants were asked whether they had ever intentionally microdosed cannabis, psilocybin mushrooms, LSD or MDMA.
The results suggest that cannabis is the most commonly microdosed substance. About 9.4% of U.S. adults — an estimated 24.1 million people — reported microdosing cannabis at least once in their lifetime. In comparison, 5.3% reported microdosing psilocybin, 4.8% LSD and 2.2% MDMA.
Ongoing microdosing was less common but still measurable: roughly 3.3% of adults reported currently microdosing cannabis, compared with about 1.0% for psilocybin, 0.6% for LSD and 0.3% for MDMA.
The study also found that the reasons for microdosing differed by substance. Cannabis microdosing was most often reported for medical reasons, including managing anxiety, depression or chronic pain. In contrast, psilocybin, LSD and MDMA were more frequently microdosed for recreational purposes, such as achieving a milder psychoactive experience.
Researchers also observed patterns tied to mental health and policy environments. Across substances, people reporting poorer mental health were more likely to report microdosing. For example, cannabis microdosing was reported by about 21% of adults who rated their mental health as "poor," compared with about 8% among those reporting "excellent" mental health.
In addition, microdosing of psychedelics such as psilocybin and LSD was more common in places where laws were more permissive — meaning, jurisdictions that have decriminalized psychedelic possession. The findings suggest that changes in drug policy may influence both access to these substances and people's willingness to report using them.
Despite growing public interest, the researchers emphasize that scientific evidence on the health effects of microdosing remains limited. Few placebo-controlled clinical trials have been conducted and existing studies have produced mixed findings about potential benefits. Additional risks stem from the unregulated nature of many of these substances, including the possibility of adulterated products or dosing errors — especially since most people who microdose do not test the substances they use.
"There's a lot of anecdotal enthusiasm around microdosing, especially for mental health," said Leas. "But we still need rigorous studies to determine whether these perceived benefits are real, who might benefit and what the potential risks could be."
The authors note that because the study was cross-sectional, it cannot determine whether microdosing influences mental health outcomes or whether people experiencing mental health challenges are more likely to try microdosing. Future research, including longitudinal studies and clinical trials, will be needed to clarify those relationships.
As cannabis legalization and psychedelic policy reforms continue to evolve across the United States, the researchers say monitoring patterns of microdosing will become increasingly important for public health.
"Microdosing appears to be a growing behavior that cuts across different substances and motivations," Leas said. "Understanding how and why people are using these small doses is essential if we want to develop evidence-based policies and guidance for clinicians and the public."
Link to full study: https://doi.org/10.1016/j.amepre.2026.108381
Additional co-authors on the study include: Joseph Friedman, MD, and Siyuan Ping from UC San Diego. Nora Satybaldiyeva, PhD, and Wayne Kepner, PhD, from Stanford University.
The study was funded, in part, by the U.S. National Institute on Drug Abuse (grant #K01DA054303, PI: Leas). Satybaldiyeva acknowledges salary support from the National Heart, Lung, and Blood Institute (grant #5T32HL161270-03). Kepner acknowledges salary support from the National Institute on Drug Abuse of the National Institutes of Health (#T32DA035165), and the William and Katharine Duhamel Addiction Medicine Fund.
Authors declare no competing interests.
