Background: Microdosing psychedelics is the practice of taking small, sub-hallucinogenic doses of lysergic acid diethylamide or psilocybin-containing mushrooms. Despite its surging popularity, little is known about the specific intentions to start microdosing and the effects of this practice. Aims: First, we aimed to replicate previous findings regarding the subjective benefits and challenges reported for microdosing. Second, we assessed whether people who microdose test their substances before consumption. Third, we examined whether having an approach-intention to microdosing was predictive of more reported benefits. Methods: The Global Drug Survey runs the world’s largest online drug survey. Participants who reported last year use of lysergic acid diethylamide or psilocybin in the Global Drug Survey 2019 were offered the opportunity to answer a sub-section on microdosing. Results: Data from 6753 people who reported microdosing at least once in the last 12 months were used for analyses. Our results suggest a partial replication of previously reported benefits and challenges among the present sample often reporting enhanced mood, creativity, focus and sociability. Counter to our prediction, the most common challenge participants associated with microdosing was ‘None’. As predicted, most participants reported not testing their substances. Counter to our hypothesis, approach-intention – microdosing to approach a desired goal – predicted less rather than more benefits. We discuss alternate frameworks that may better capture the reasons people microdose. Conclusion: Our results suggest the perceived benefits associated with microdosing greatly outweigh the challenges. Microdosing may have utility for a variety of uses while having minimal side effects. Double-blind, placebo-controlled experiments are required to substantiate these reports.