Before being announced as President-elect Donald Trump’s nominee for the top position at the nation’s healthcare insurance regulator, Dr. Mehmet Oz gained notoriety for advocating dubious medical treatments on his popular daytime talk show.

His assertions about products promising weight loss without changes to diet or exercise were scrutinized during a Senate hearing in 2014. In a 2015 letter, ten doctors called for Oz’s removal from the faculty at Columbia University.

“Dr. Oz has consistently shown a disregard for science and evidence-based medicine, alongside an unfounded resistance to genetically engineered food crops,” they wrote, as reported by CBS News. “Most alarmingly, he has displayed a severe lack of integrity by advocating ineffective treatments and remedies for personal financial gain.”

Although Oz is a qualified heart surgeon with educational credentials from Harvard University and the University of Pennsylvania, his rise to fame began as a frequent guest on “The Oprah Winfrey Show.” He later hosted “The Dr. Oz Show” from 2009 until 2022, before he launched a campaign for the U.S. Senate in Pennsylvania as a Republican, ultimately losing to Democrat John Fetterman.

“He is an exceptional surgeon,” remarked Dr. Pieter Cohen, an associate professor at Harvard Medical School. “While he initially shared valuable insights, over time he started to venture into areas lacking scientific backing, promoting ideas detrimental to consumer welfare.”

Trump announced his intent to nominate Oz to direct the Centers for Medicare and Medicaid Services (CMS), the federal body that manages the two significant government-sponsored health insurance programs, which together serve over 145 million Americans, oversees quality assessments of hospitals and nursing homes, and executes healthcare reforms mandated by the Affordable Care Act.

Liz Huston, spokesperson for the Trump-Vance transition team, stated Oz “ has advocated for the core principles of Making America Healthy Again for many years.” She remarked that he will be “an invaluable asset to the Trump-Vance administration, bringing expert leadership and a steadfast commitment to authentic healthcare reform.”

An interview request sent via Oz’s website has yet to receive a response.

Cohen criticized Oz for presenting a segment about a weight loss plan that advised consuming only 500 calories daily—the average adult typically needs about 2,000 calories—while also taking supplements of a pregnancy hormone. “Weight loss will happen if you’re not consuming food, therefore the (hormone) was irrelevant,” he pointed out.

Cohen added that Oz should have focused on the potential issues with this weight loss method instead of featuring individuals who lost weight using it, which misleadingly suggested that the hormone treatment was responsible for their success.

A controversial Senate hearing

At the start of the 2014 Senate hearing, the panel aired a video of Oz claiming, “You may think magic is just an illusion, but this little bean has scientists declaring it a miracle weight loss cure that works for everyone.” He was referencing a study on green coffee beans, which the researchers later retracted, according to the New York Times.

Then-Sen. Claire McCaskill, a Democrat from Missouri, questioned Oz directly: “I don’t understand why you promote these claims when you know they lack truth. Why would you undermine your show’s credibility with statements like these?”

Oz maintained that he never personally sold supplements and would end each show by clarifying so. He claimed that his segments were misrepresented by con artists looking to promote their products and accepted responsibility for the “emotional language” he used in describing them.

“My show has moderated our editorial stance concerning promising supplements,” he stated. “We have improved our standards for presenting opportunities and have included dissenting opinions within those segments.”

Support from Senate Republicans

The Centers for Medicare and Medicaid Services is responsible for managing the two major health insurance programs. Each year, the agency determines the payments Medicare makes to doctors and hospitals for various services, and these rates often influence private insurance companies’ coverage decisions.

If confirmed, Oz may enable the agency to cover treatments that have not yet been reviewed by the Food and Drug Administration or have limited supportive evidence, as reported by Inside Health Policy.

“Dr. Oz will lead efforts to encourage disease prevention, ensuring we achieve optimal outcomes for every dollar spent on healthcare in our great nation,” Trump stated during his announcement. “He will also work to eliminate waste and fraud within our country’s most expensive government entity, which accounts for a third of our national health expenditure and a quarter of the entire federal budget.”

Some Democrats are criticizing Oz’s track record.

“Dr. Oz is well-known for promoting misleading information to unsuspecting Americans without facing any repercussions,” said Sen. Ron Wyden, a Democrat from Oregon, in a statement. “Americans deserve a leader at CMS who will resist pressure from Big Pharma and insurance scammers misleading seniors and denying necessary healthcare, and I’m uncertain if a talk show host fits that role.”

However, Republicans are generally in favor of Oz’s nomination, which is all he needs for confirmation in a Senate where they are in the majority. This opinion is shared by moderate Senator Susan Collins from Maine, who mentioned to POLITICO, “Having someone with experience as a health care provider in charge of that agency could provide a unique perspective.”