Microdosing—taking very low doses of psychedelics like psilocybin or LSD without full-blown effects—has been promoted as a way to boost thinking skills. A meta-analysis of 14 studies with 1,614 participants found that microdosing actually reduced cognitive control, with no improvement in other cognitive domains. The type of substance, dose, or duration of microdosing did not change this result, and effects were similar whether measured while on the drug or after. This suggests microdosing may disrupt top-down cognitive control, consistent with models of how psychedelics reduce mental rigidity. More research is needed to separate temporary drug effects from lasting changes.
MDMA temporarily raises oxytocin levels in a time-dependent way, with the peak occurring between 150 and 200 minutes after administration, then declining. A systematic review and meta-analysis of ten studies (39 effect size estimates) found that the dose of MDMA did not significantly predict changes in oxytocin. A trend suggested that samples with more female participants showed smaller increases in oxytocin. These findings indicate that MDMA's prosocial effects may be linked to this transient oxytocin elevation, which could inform the timing of MDMA-assisted psychotherapy sessions. Standardized methods and larger studies are needed to clarify these effects.