INTRODUCTION: Microdosing involves consuming low doses of psychoactive substances, typically 1/5th to 1/20th of a recreational dose. Despite increasing public attention to cannabis and psychedelics amid evolving drug policies, epidemiological data on microdosing remain limited.
METHODS: A cross-sectional, web-based survey (Characterizing the Epidemiology of Cannabidiol Use Survey) of 1,525 US adults was conducted in October-November 2023 and analyzed in 2024-2025 using Ipsos KnowledgePanel. Participants reported lifetime microdosing of cannabis, psilocybin, lysergic acid diethylamide (LSD), and 3,4-Methylenedioxymethamphetamine (MDMA). Lifetime prevalence, frequency, and reasons for microdosing were assessed, along with associations with demographics, mental health, quality of life, and cannabis and psychedelic policy environments. Survey weights were applied to generate nationally representative estimates.
RESULTS: Cannabis was the most commonly microdosed substance (9.4%; 95% CI=8.0, 10.7; 24.1 million adults), followed by psilocybin (5.3%; 95% CI=4.3, 6.3; 13.7 million adults), LSD (4.8%; 95% CI=3.8, 5.9; 12.4 million adults), and MDMA (2.2%; 95% CI=1.5, 2.9; 5.7 million adults). Cannabis (41.2%; 95% CI=33.3, 49.5) was primarily microdosed for medical purposes (e.g., "to manage pain"), while psilocybin (66.6%; 95% CI=56.9, 75.1), LSD (59.2%; 95% CI=46.5, 70.8) and MDMA (86.0%; 95% CI=68.8, 94.5) were more commonly microdosed for recreational purposes (e.g., "to get less high"). Across all substances, lifetime microdose use was more prevalent among respondents reporting poorer mental health and among those residing in jurisdictions permitting recreational cannabis use and decriminalized psychedelic possession.
CONCLUSIONS: Despite remaining illegal at the federal level, a considerable number of US adults reported microdosing cannabis, psilocybin, LSD, and MDMA in their lifetime. Microdosing was associated with poorer mental health and was more common among respondents who lived in environments with fewer restrictions on the use of cannabis and psychedelics. As policy reforms continue to expand, microdosing prevalence may increase, making ongoing surveillance essential for evidence-based public health responses.
