Menstrual Cycle Status and the Acute Subjective Psychedelic Experience

Background: Individual differences shape the acute subjective psychedelic experience, but menstrual cycle status remains an understudied source of potential variability.Methods: In a longitudinal observational study, 169 participants reported psychedelic use during the two-month study period. Participants were classified by menstrual cycle status during their most intense psychedelic experience: menstruating during the experience (n=15), menstruating but not during the experience (n=60), not menstruating (n=25), and male participants (n=69). Primary analyses examined associations between cycle status and ego dissolution (Ego Dissolution Inventory; EDI), mystical-type experience (Mystical Experience Questionnaire; MEQ), and challenging experience (Challenging Experience Questionnaire; CEQ), adjusting for dose and age. Exploratory analyses examined MEQ and CEQ subscales and post-acute risk of harm to self and others.Results: Participants menstruating during their experience reported higher EDI scores than both those menstruating but not during the experience and male participants (β=−0.89 and −0.68, ps≤.011). Cycle status was not associated with MEQ or CEQ scores. Exploratory analyses found higher physical distress and death subscale scores among participants menstruating during their experience than among those menstruating but not during the experience (β=−0.77 and −0.80, ps≤.005). Risk of post-acute harm to self and others was higher among those menstruating during the experience than among those menstruating regularly but not during the experience (OR=6.41, p=.022).Conclusions: Menstrual cycle timing may be associated with aspects of the acute psychedelic experience, specifically ego dissolution and potentially risk of post-acute harm to self and others. These preliminary findings support further investigation of menstrual cycle status in psychedelic research.