When Ayahuasca Microdosing Might Cause Serotonin Toxicity

Kelan Thomas, PharmD, MS, BCPS, BCPP

I have recently noticed several websites advertising and selling commercial products for “ayahuasca microdosing,” but unlike microdosing with the classic psychedelic serotonin 2A receptor agonists psilocybin or LSD, microdosing with ayahuasca has a unique pharmacologic effect due to β-carboline alkaloids (harmaline, harmine, tetrahydroharmine) contained in the Banisteriopsis caapi (B. caapi) vine. While there has been promising evidence of safety and effectiveness for ayahuasca macrodosing to treat depression, the medical risks and benefits of ayahuasca microdosing remain unknown (Palhano-Fontes et al., 2019). As a board-certified psychiatric pharmacist, one of my primary responsibilities is to educate clients about psychotropic medications so they can evaluate the risks and benefits to make informed treatment decisions, so I wanted to discuss the potential for ayahuasca microdosing to have drug-drug interactions that could possibly cause serotonin toxicity... continue reading.