one overdose?
Under our direction, no, and we are not aware of people being harmed from even large doses of Ayahuasca, when the shamanic work directing the trance state is done completely and well. In fact, Ayahuascero shamans will, on occasion, take a very large dosage to induce a very deep and powerful trance and explore new psychic territory. This is recommended for experienced shamans only, of course.