Dennis Jon McKenna is an American ethnopharmacologist, research pharmacognosist, lecturer and author. He who has studied plant hallucinogens for over forty years.
He earned his Master's degree in botany at the University of Hawaii, and his Doctorate in Botanical Sciences from the University of British Columbia.
Since that time, he has conducted extensive ethnobotanical fieldwork in the Peruvian, Colombian, and Brazilian Amazon.
He is the brother of well-known psychedelics proponent Terence McKenna.
He is a founding board member and the director of ethnopharmacology at the Heffter Research Institute, a non-profit organization concerned with the investigation of the potential therapeutic uses of psychedelic medicines.