[24] Kilham is an activist in the movement to legalize marijuana[25] and has written about the topic, including the use of cannabis for medicinal purposes and U.S. patent 6.630.507.

[30][better source needed] He researches and promotes psychoactive and psychedelic plants used in traditional shaman rituals, including kava and ayahuasca.

[31] He has written a book about the medicinal qualities of psychoactive and psychedelic plants, entitled Psyche Delicacies: Coffee, Chocolate, Chiles, Kava and Cannabis and Why They're Good for You.

Kilham's Ayahuasca Monologues have been described as a “psychedelic TED talk” and “Insightful, funny, wild, and totally real".

Students experience the Amazon while learning about field expedition, sustainability, shamanism, and medicinal plants of the region.

[7][47] Kilham is the author of fourteen books and numerous publications on medicinal plants, natural products, and yoga, including The Five Tibetans: Five Dynamic Exercises for Health, Energy, and Personal Power and Stalking the Wild Orgasm,[48] which appears in the 1988 movie, Earth Girls Are Easy.

Kilham's other books are: Kilham is a frequent guest on The Dr. Oz Show with Dr. Mehmet Oz, appearing on at least 15 occasions from January 2008 to January 2015,[49][50][51] [40][52][53][54] and Good Morning America, where he has appeared to discuss herbal remedies, his cocoa sustainability project, and libido boosting plants.