Psychedelics and women's mental health: the effects of female sex hormones on psychedelics' efficacy and tolerability.
Kuypers Kim P C KPC, Mason Natasha L NL, Carlier Aurelie A, Totomanova Iva I et al.
Women experience a disproportionate burden of affective and stress-related disorders, with symptom variability shaped by endocrine transitions across the menstrual cycle, pregnancy, postpartum, and menopause. Although psychedelic-assisted therapies are increasingly investigated for these conditions, hormonal state represents a largely unaccounted determinant of variability in exposure, response, and tolerability. This narrative review synthesizes clinical, preclinical, and neuroimaging literature to examine how estradiol and progesterone modulate psychedelic pharmacokinetics, pharmacodynamics, and large-scale brain network dynamics implicated in psychiatric disorders. At the pharmacokinetic level, sex hormones influence gastrointestinal physiology (including gastric pH and transit time), tissue distribution via body composition and fluid balance, and hepatic metabolism through modulation of CYP450 enzymes, particularly CYP3A4 and CYP2D6, which are key pathways for LSD and psilocin biotransformation. Renal elimination plays a comparatively minor role. These processes may collectively alter onset, peak concentration, and systemic exposure across hormonal states, although direct human data for psychedelics remain absent. At the pharmacodynamic level, estradiol and progesterone regulate serotonergic signaling, including dynamic modulation of 5-HT2A receptor density and binding across the menstrual cycle and reproductive lifespan. Platelet, PET, and SPECT studies indicate higher 5-HT2A availability in low-progesterone states and reduced availability in progesterone-dominant or hypoestrogenic states. Beyond 5-HT2A, psychedelics engage broader serotonergic, glutamatergic, and GABAergic systems that converge on prefrontal-limbic, default mode, and salience networks, circuits that are also dysregulated across depression, anxiety, and trauma-related disorders. Hormonal fluctuations may further influence subjective intensity and tolerability, with potential sensitivity peaks in the early-mid follicular and early luteal phases, although direct evidence remains limited. Together, these findings suggest sex hormones as a mechanistically plausible, clinically relevant but under-characterized source of variability in psychedelic treatment response.