I am currently providing Ketamine for PTSD and treatment resistant depression. Cool to see someone that has been suicidal for decades walk out and be free of it. Opens pathways for making rapid gains in therapy.
MDMA has run into a stumbling block at the FDA and will be delayed for awhile yet.

IM dosing is 0.5 to 1.25 mg per Kg. Typically 40 to 70 mg for the first dose and then I offer a booster of 20 to 30 mg. Full dissociative state without any respiratory depression. Sessions is 3 hours, 10 minutes discussing expectations, 15 minute meditation, first injection, booster at 15 minutes if they consent. About 45 60 minutes while they are on their journey and then an hour to wake up, do some processing, have a snack, cup of tea, ambulate to the bathroom. Discharged to their driver. Their is also prep work the day before along with the intake, and a followup call the next day to further process the experience and set up the next treatment if desired. Not an FDA approved indication, so insurance will not cover it. I accept referrals only from therapists that know me and have been working with the person for a while.

This is typical for psychiatric IM practices. Infusion clinics have different processes.

Set and Setting is very important. Side effects are rare and minor. The bad trips occur when not prepared or ambushed by the drug. MDMA in a quiet room with a therapist is a very different experience than at a Rave after dancing for 8 hours and drinking 6 red bulls.
Shamans have been using these substances for 100s 1000s? of years. Peyote, Ayahuasca, psilocyban. European conquerers only had alcohol and didn't understand psychedilics and tried to extinguish the cultures.
About 8 years ago I started asking more in depth questions about psychedelic use during addiction intakes. Almost universally described as great experiences that sometimes would lead to significant periods of remission. I'm waiting for the puritans to pass laws and shut it all down. My operation is on a shoestring so won't cost me much if they do.
Many providers offer experiential journeys, meaning, you don't have to have any pathology, but want to experience a great connection. Most of us have done some journeys and let me tell you it can be life changing.