Gary Michael Null (born January 6, 1945) is an American talk radio host and author who advocates pseudoscientific alternative medicine and produces a line of questionable dietary supplements.

Null is hostile to evidence-based medicine and has accused the medical community of being in a cabal with the pharmaceutical industry to suppress novel treatments for economic gains.

[1] Null holds strong anti-vaccination views and rejects the scientific consensus on topics such as water fluoridation, genetically modified organisms, and electromagnetic fields.

[8] He later enrolled in a Ph.D. program in human nutrition and public health sciences from Union Institute & University,[7] a private distance-learning college headquartered in Cincinnati, Ohio.

[9] Null's doctoral thesis was entitled "A Study of Psychological and Physiological Effects of Caffeine on Human Health"; the degree was conferred in July 1989[10] when he was 44 years old.

[8] At the time of Null's education, Edison State College was a non-traditional institute that had no campus and conferred degrees via an external degree program, and towards which administrators evaluated "college-level learning achieved through work or life experiences, self-study, college courses taken previously, industry-sponsored education programs, military instruction" and other prior learning.

[8] Similarly, the rules for obtaining a PhD at Union Institute & University were a lot less rigid and allowed students to design their own course curriculum, form their doctoral committee, and attend only a few seminars; 13 years later, it would be subject to sanctions for failing to meet academic standards.

[8] Kurt Butler's 1992 book Consumer's Guide to Alternative Medicine raised similar questions and also reported that Null had long dodged queries about providing any relevant information (including precise time-spans) for his degrees.

[14] Over the years, Null has owned multiple business ventures attempting to sell nutritional supplements for a wide range of diseases and disorders, along with a natural gourmet restaurant, a wellness retreat and an organic farm.

[19] In 1985, Null began writing a lengthy series of reports for Penthouse titled "Medical Genocide" that asserted mainstream medicine was completely ineffective in curing a range of major ailments from cardiac diseases to arthritis.

[24] Seth Kalichman, professor of social psychology at the University of Connecticut, has decried Null's role as a prominent proponent of AIDS denialism and has accused him of cashing in on HIV/AIDS.

[24] In 2010, Null reported that he became ill and had to see his doctor and that six other consumers were hospitalized for vitamin D poisoning after ingesting a nutritional supplement manufactured by his own contractor.

[1] Corby Kummer noted Null's Vegetarian Handbook to contain an outlandish combination of plant foods supposedly high in protein.

[49] Butler has written that Null has provided potentially dangerous and outright dubious medical advice to a variety of patient-callers via these fora.

[52][35][53] While Null's films were highly[35] effective in generating financial contributions, the president of PBS, Ervin Duggan, expressed concern that such programming "open[ed] the door to quacks and charlatans".