DMT has been consumed throughout history and into prehistory by indigenous peoples, especially in South America, where it is consumed during shamanic rituals and called ayhuasca. This is done by combining plant material that contains it with a monoamine oxide inhibitor, a special chemical that allows the drug to avoid digestion by the stomach and reach the bloodstream. Evidence of DMT consumption by indigenous peoples in South America stretches back to at least 2130 BC. A pipe made from puma bone of that age was tested positive for the substance. Smoking it would give the users visions and feelings that they associated with magical sources, putting them into contact with “spirits” they could consult on matters of plants, disease, etc.