Estimating Cardiac 5-HT2B Safety Margins for Repeated Low-Dose Psilocybin Using an Exposure-Response Model

This modelling study, supported by a rat experiment, assessed whether repeated low-dose psilocybin could pose a heart valve risk by acting on the 5-HT2B receptor. It found a 3 mg daily regimen had a large safety margin in the model, and rats exposed to higher psilocin levels for 12 days showed no valve damage, though slow fibrosis could not be ruled out.