Oprah Winfrey said that she was stepping down from the board of Weight Watchers, a few months after going public about taking a medication for weight loss.
The entertainment mogul has been the most prominent spokeswoman for Weight Watchers since joining its board in 2015, helping it weather competition from other weight loss companies while opening up a broader conversation around obesity and diet.
Her endorsement of Weight Watchers — she has said she lost 40 pounds using the company’s point system — convinced many others to sign up, analysts said.
The announcement sent Weight Watchers shares into a tailspin, with stock falling 25 percent in early trading Thursday.
The company said in a special filing with the Securities and Exchange Commission on Wednesday that Ms. Winfrey had notified the chairman that she would not be standing for re-election in May, concluding a nearly nine-year tenure on the board.
“Her decision was not the result of any disagreement with the company on any matter relating to the company’s operations, policies or practices,” Weight Watchers said in the filing.
Ms. Winfrey, who has spent decades as a dominant figure in the country’s conversations about weight and dieting, revealed in December that she was taking a weight-loss medication.
“The fact that there’s a medically approved prescription for managing weight and staying healthier, in my lifetime, feels like relief, like redemption, like a gift, and not something to hide behind and once again be ridiculed for,” she told People Magazine.
In a statement from the company on Thursday, Ms. Winfrey said that she planned to continue advising the chief executive of Weight Watchers, Sima Sistani, on “elevating the conversation around recognizing obesity as a chronic condition.”
A representative for Ms. Winfrey did not offer additional comment.
The company said in the statement that Ms. Winfrey would donate the value of her holdings in Weight Watchers to the National Museum of African American History and Culture in Washington in part to “eliminate any perceived conflict of interest around her taking weight loss medications.”
The company did not explain the conflict of interest, and a spokeswoman for Weight Watchers did not immediately respond to a request for comment.
She owned about 1.13 million shares worth $6.34 million, according to a Securities and Exchange Commission filing on Jan. 1.
Ms. Winfrey has not specified which weight-loss drug she was taking. In 2021, researchers found that semaglutide, a drug to treat diabetes, produced dramatic weight-loss results among patients with obesity. Since then, demand has soared for new drugs like Ozempic, Wegovy and Zepbound that can help people lose weight, in part by suppressing appetite.
The emergence of such drugs has posed a business challenge to diet plans like Weight Watchers. But the company is pivoting toward a business model based on its ability to obtain the limited supply of the much-coveted weight-loss drugs.
Last year, Weight Watchers acquired Sequence, a subscription telehealth platform that offers, among other benefits, access to healthcare providers who can prescribe weight-loss drugs including Ozempic, for $106 million. (Users pay $99 a month, not including prescription costs.) The company also dropped some of its in-person meeting offerings, a well-known tool in its weight-loss plans, inspiring some customers to organize their own support groups.
After an initial run following the acquisition of Sequence, Weight Watchers stock has lost more than half its value this year.
Shares of the New York City-based company have been hurt because of “exacerbated concerns” around its growth prospects and liquidity, Stephanie Davis, a Barclays analyst, said.
“It’s still early in its turnaround story from being more of an in-person dieting model to changing to a digital health company,” Ms. Davis said in an interview, adding that “transitions have a lot of risk.”