Meta-analysis finds MDMA raises oxytocin, peaking 150 to 200 minutes after administration and remaining slightly elevated for up to five hours

A meta-analysis of 10 human studies with 39 effect size estimates finds that MDMA produces a sustained increase in circulating oxytocin, with levels rising after administration, peaking 150 to 200 minutes later, and remaining slightly elevated above baseline in some studies for up to five hours. The timing may help researchers schedule psychotherapy interventions in trials for conditions such as PTSD, where MDMA is investigated for its prosocial and emotional-processing effects. The analysis found no statistically significant relationship between MDMA dose and oxytocin levels, while a possible sex-related difference was also nonsignificant. Time, dose, and sex explained only about a quarter of the variation, indicating important unmeasured biological factors. Interpretation is limited because blood and urine oxytocin may not directly reflect brain activity, methods differed across studies, and publication bias was detected. Larger studies with standardized dosing and hormone extraction methods are needed.