Dennis Jon McKenna (born December 17, 1950) is an American ethnopharmacologist, research pharmacognosist, lecturer and author. He is the brother of well-known psychedelics proponent Terence McKenna and 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. Description above from the Wikipedia article Dennis McKenna, licensed under CC-BY-SA, full list of contributors on Wikipedia.