[7] He spent the next four years as chief academic and scientific officer of the St. John Providence Health System, Detroit, before joining the Baylor University Medical Center in 2014.
McCullough told The Wall Street Journal that the urgency of the public health crisis justified compromises on best practices in medical research.
[25] In August 2020, McCullough, Harvey Risch of the Yale School of Public Health, and co-authors published an observational study proposing an early outpatient treatment regimen for COVID-19 in the American Journal of Medicine.
The article was shared on social media, mainly by groups which had previously published COVID-19 misinformation, in posts falsely interpreting the publication as an official endorsement by the journal itself of hydroxychloroquine as a treatment for COVID-19.
Ashish Jha, dean of the Brown University School of Public Health, called to testify by the ranking member, said the "clear consensus in the medical and scientific community, based on overwhelming evidence" is that hydroxychloroquine is ineffective as a treatment for COVID-19.
[26][45][46][47] Jha responded on The New York Times opinion page, "By elevating witnesses who sound smart but endorse unfounded therapies, we risk jeopardizing a century's work of medical progress.
[29] Posted on the Canadian online video sharing platform Rumble, McCullough gave an interview in April 2021 to The New American, the magazine of the right-wing John Birch Society, in which he advanced anti-vaccination messaging, including falsely claiming huge numbers of fatalities attributed to the COVID-19 vaccines.
[4][23][50][51] In December 2021, McCullough appeared on the Joe Rogan Experience promoting debunked conspiracy theories and misinformation (e.g. the COVID-19 pandemic was planned, the spike protein causes cell death, medical authorities are conspiring to illegitimately suppress hydroxychloroquine and ivermectin).