An open-label trial to test menstrual cycle effects and tolerance to low dose psilocybin in healthy menstruating persons (PsiMen).

The menstrual cycle causes major fluctuations in hormones. Changes to progesterone and estrogen in particular are known to dramatically affect not just reproductive systems but brain function. Females are majorly overrepresented in adverse reactions to common medications which suggests that menstrual cycle linked hormones may not just change disorder symptoms but also the response to drug therapies. We will study how the brain’s response to a drug changes over the menstrual cycle. In this study we will examine how the menstrual cycle may change how females are affected by the drug psilocybin. We will study this by taking blood samples and using standardised questionnaires. We will test the hypotheses that the pharmacokinetics and pharmacodynamics of psilocybin are modified across the menstrual cycle. This research may help to improve treatments by taking the menstrual cycle into account and potentially reduce symptoms and adverse reactions over the menstrual cycle.