His views on health and nutrition are at odds with scientific consensus; psychiatrist Stephen Barrett, co-founder of the National Council Against Health Fraud and webmaster of Quackwatch, described Null as "one of the nation's leading promoters of dubious treatment for serious disease".
On his radio show, and in books and self-produced movies, Null attacks the medical community, promotes a range of alternative cancer treatments, denies that HIV causes AIDS, opposes genetically modified foods, and promotes dietary supplements which he produces.
In 2010, Null reported that he and six other consumers had been hospitalized from vitamin D poisoning, after ingesting a nutritional supplement carrying his name and endorsement. Null sued a contractor involved in producing the product, alleging that each contained more than 1,000 times the dose of vitamin D reported on the label.
Null was raised in Parkersburg, West Virginia, with his two brothers. He holds an associate's degree in business administration from the 2-year, for-profit Mountain State College in Parkersburg, West Virginia and a Bachelor's degree from Thomas Edison State College in Trenton, New Jersey.
Null holds a Ph.D. in human nutrition and public health sciences from Union Institute & University, a private distance-learning college headquartered in Cincinnati, Ohio. Null's doctoral thesis was entitled "A Study of Psychological and Physiological Effects of Caffeine on Human Health".
His credentials, including the degree-granting practices at Edison State and the rigor of the Ph.D. program at Union Institute, have been questioned by Stephen Barrett on his Quackwatch website, who labeled Null as "one of the nation's leading promoters of dubious treatment for serious disease" and a fraud. The Union Institute's Ph.D. program came under scrutiny by the Ohio Board of Regents in the late 1990s, early 2000s which culminated in its 2002 Reauthorization Report. The report was critical of the Union Institute's Ph.D. program, noting in particular that " ... expectations for student scholarship at the doctoral level were not as rigorous as is common for doctoral work ... " (OBR 2002 Reauthorization Report, page 13) As a result, The Union was put on probation, the Union Graduate School was dissolved and the Ph.D. program was restructured.
Null attacks many facets of mainstream medicine, arguing that physicians and pharmaceutical companies have an economic interest in promoting rather than preventing sickness. In the 1979-80, he co-authored a series of articles on cancer research for Penthouse, entitled The Politics of Cancer beginning with one entitled "The Great Cancer Fraud." Null's writings in Penthouse accused the medical community of "suppressing alternative cancer treatments to protect the medical establishment's solid-gold cancer train." In place of standard medical therapy, Null advocated alternative cancer treatments such as hydrazine sulfate. A series of three articles co-authored by Null in Penthouse is credited by David Gorski with bringing the Burzynski clinic to prominence. In 1985, Null began writing a lengthy series of reports for Penthouse entitled "Medical Genocide". In 1999 TIME wrote of Null: "From a young reporter this is to be expected. But two decades later, Null, 54, is still warning of a variety of medical bogeymen out to gull a trusting public."
Null was the keynote speaker at a rally opposing mandatory H1N1 influenza vaccination during the 2009 flu pandemic, leading the New York State Department of Health to dismiss Null's claims about the vaccine as "not scientifically credible." The New York State Health Commissioner held a conference at the time of the rally to discuss the clinical trials which were used to demonstrate its safety.
In addition to his promotion of alternative cancer treatments and condemnation of the medical establishment, Null has argued that HIV is harmless and does not cause AIDS. In his book AIDS: A Second Opinion, Null advocated a range of dietary supplements for HIV-positive individuals instead of antiretroviral medication. In 2002, Salon.com described the book as "massive, irresponsible and nearly unreadable."
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; in Kalichman's 2009 book, Denying AIDS, he compared Null's activities to Holocaust denial and described Null as an example of a dangerous entrepreneur who "obviously breached" the balance between free speech and protecting public health.
Null began broadcasting a syndicated radio talk show, Natural Living with Gary Null in 1980. His show was broadcast first on WBAI, then on the VoiceAmerica Network and over the internet. Null's show subsequently returned to WBAI, leading to protests from ACT-UP New York and other AIDS activist groups concerned by Null's promotion of AIDS denialism. He continues to host The Gary Null Show through the Progressive Radio Network, which he established in 2005.
Null has made several self-funded and self-produced documentary films on public policy issues, personal health, and development. His videos had been aired by PBS during pledge drives, which led to a surge in sales of his books. Null has also claimed that in his two pledge drive appearances, he raised more than $6 million for PBS stations; a claim that PBS would not confirm. Concerns arose within PBS over the videos' sensational claims with the Seattle affiliate cancelling a planned rebroadcast and Ervin Duggan, the president of PBS, expressing concern that by showing Null's videos, the network was "open[ing] the door to quacks and charlatans."
In his 2013 blog post, "Gary Null, Cultivator of Dangerous Woo, Plants Seeds of Death", Discover magazine's Keith Kloor condemns Null's 2012 documentary film Seeds of Death: Unveiling the Lies of GMOs, writing that the film:
...is a classic collection of all the untruths, myths, and tropes commonly used by the anti-GMO movement. The scope of its dishonesty is brazen... This is crazy train stuff said with a straight face. The worldview that allows someone to believe such things cannot be penetrated with legitimate scientific information.
In 2010, Null reported that he and six other consumers had been hospitalized for vitamin D poisoning after ingesting a nutritional supplement manufactured for his line of supplements by a contractor. In a lawsuit against the company, he alleged that the supplement erroneously contained more than 1,000 times the dose of vitamin D reported on the label.
The Los Angeles Times wrote that Null's experience "should give pause to anyone lured by the extravagant claims of many supplements makers", and said that it was common for dietary supplements to contain doses "wildly different than those indicated on their label" as a result of weak regulation.
Null has self-produced a number of low-cost advocacy films including:Poverty Inc (2014)
Autism: Made in the U.S.A.(2009)
Gulf War Syndrome: Killing Our Own (2007)