The High DMT Dose Experience

In 1990, Dr. Rick Strassman administered high doses of the powerful psychedelic DMT (Dymethyltriptamine) to 60 volunteers at the University of New Mexico's School of Medicine in Albuqerque, then  in 2000 he published "DMT The Spirit Molecule", a book about that  experimental research which included many volunteers' experience reports at various level of dosage. Ten years later, in 2010, Dr. Strassman co-produced a documentary film by the same name, directed by Mitch Schultz (youtube)
See here the extremely detailed and engaging experience report  of the Mexican shaman Patricio Dominguez, one of the volunteers of that historical investigation