Please use this link to access this publication. Abstract Introduction A clinical trial of Epidiolex®, the only US FDA-approved cannabis-derived consumer product (CDP), discovered an interaction with an immunosuppressant (tacrolimus) that led to drug toxicity, highlighting the unique intersection of prescription and commonly unregulated consumer products. Objective We aimed to identify if similar drug–drug interactions (DDIs) are occurring among the consumer CDP market, even though they cannot be identified through trials. Methods We searched Reddit for subreddits related to CDPs or health, resulting in 63,561,233 posts. From these, we identified 190 posts discussing both immunosuppressants and CDPs. Two blinded investigators evaluated the following. (1)...