Richard Evans Schultes (1915-2001) was a Jeffrey Professor of Biology and Director of the Botanical Museum at Harvard University, considered by many to be the father of modern ethnobotany.

Albert Hofmann (1906-2008), the father of LSD, was a world-renowned scientist, member of the Nobel Prize Committee, Fellow of the World Academy of Sciences, and member of the International Society of Plant Research and of the American Society of Pharmacognosy. He was a leader in pharmaceutical-chemical research and the author of several books, including LSD: My Problem Child.

Christian Rätsch, Ph.D. (1957 – 2022), was a world-renowned anthropologist and ethnopharmacologist who specialized in the shamanic uses of plants for spiritual as well as medicinal purposes. He studied Mesoamerican languages and cultures and anthropology at the University of Hamburg and spent, altogether, three years of fieldwork among the Lacandone Indians in Chiapas, Mexico, being the only European fluent in their language. He then received a fellowship from the German academic service for foreign research, the Deutsche Akademische Auslandsdienst (DAAD), to realize his doctoral thesis on healing spells and incantations of the Lacandone-Maya at the University of Hamburg, Germany.

In addition to his work in Mexico, his numerous fieldworks have included research in Thailand, Bali, the Seychelles, as well as a long-term study (18 years) on shamanism in Nepal combined with expeditions to Korea and the Peruvian and Colombian Amazon. He also was a scientific anthropological advisor for expeditions organized by German magazines such as GEO and Spektrum der Wissenschaften (Spectrum of Sciences).

Before becoming a full-time author and internationally renowned lecturer, Rätsch worked as professor of anthropology at the University of Bremen and served as consultant advisor for many German museums. Because of his extensive collection of shells, fossils, artifacts, and entheopharmacological items, he had numerous museum expositions on these topics.

He is the author of numerous articles and more than 40 books, including Plants of Love, Gateway to Inner Space, Marijuana Medicine, The Dictionary of Sacred and Magical Plants, and The Encyclopedia of Psychoactive Plants. He is also coauthor of Plants of the Gods, Shamanism and Tantra in the Himalayas, Witchcraft Medicine, Pagan Christmas, and The Encyclopedia of Aphrodisiacs and was editor of the Yearbook of Ethnomedicine and the Study of Consciousness. A former member of the board of advisors of the European College for the Study of Consciousness (ECSC) and former president of the Association of Ethnomedicine, he lived in Hamburg, Germany.