How do I choose a safe and ethical ayahuasca retreat?

Ask hard questions before you send money. Who are the facilitators, how long have they trained, and with whom? What's the medical screening, and is there a doctor on call? What's the participant-to-facilitator ratio, and what happens if you have a hard night? How do they handle boundaries, especially around touch and one-on-one time? Talk to two or three past participants directly. Any retreat that gets defensive about these questions is telling you something.