Age and ovarian hormones change rats' behavioral responses to psilocybin, with estrous phase and adolescence shaping sensitivity and drug effects

Psilocybin affects rats differently depending on age and ovarian hormone status. Adolescent females and adult females in specific estrous phases show altered behavioral sensitivity, suggesting that reproductive hormones and developmental stage can shape psychedelic responses. The findings center on preclinical behavioral measures in rats, likely including signs linked to serotonergic activation and drug sensitivity. Differences across adolescence versus adulthood and across hormone states point to biological variables that may meaningfully influence dose response, timing, and observable effects. Sex hormones and developmental timing matter for psychedelic science because they can complicate simple one-size-fits-all assumptions. Preclinical evidence like this can inform future mechanistic work and may eventually improve how human studies consider age, sex, cycle phase, and individualized treatment design for psilocybin.