Talk about throwing your weight around: Oprah Winfrey just made a $38.2 million profit — on paper, at least — after she unveiled a sweeping strategic alliance with Weight Watchers that sent its stock price soaring more than 88%.

The TV, movie, and stage star paid $43.2 million for 10% of Weight Watchers’ shares, and agreed to join its board, as part of a five-year agreement that gives it the right to use her image in endorsements. She also has options that entitle her to buy an additional 5% of the company’s stock.

“Weight Watchers has given me the tools to begin to make the lasting shift that I and so many of us who are struggling with weight have longed for,” Winfrey says. “I believe in the program so much I decided to invest in the company and partner in its evolution.”

The weight loss company says in an SEC filing that Winfrey will help to develop its program “and related initiatives,” and promote Weight Watchers in ads, promos and personal appearances. The filing makes no mention of OWN, the TV network she co-owned with Discovery.

“We are expanding our purpose from focusing on weight loss alone to more broadly helping people lead a healthier, happier life,” Weight Watchers CEO Jim Chambers says. “Through our conversations, it became clear that there is tremendous alignment between Oprah’s intention and our mission. We believe that her remarkable ability to connect and inspire people to realize their full potential is uniquely complementary to our powerful community, extraordinary coaches and proven approach.”

Winfrey’s endorsement comes at a trying time for Weight Watchers. Its shares have lost 49% of their value over the last 12 months as membership has declined. At the end of June it had 2.8 million active members paying recurring fees for meetings or online services, down 16.7% from mid-2014.

Chambers told analysts in August that people who want to lose weight now hope to “get there through a more holistic mindset of healthier eating, fitness and emotional strength, with weight loss being a critical element of this bigger picture.”

He added that the company was “getting ready to launch one of the most significant and comprehensive program innovations in the history of this company, something that we are increasingly confident will change the trajectory of our business.”

In 1999, Artal Group paid H.J. Heinz $735 million for Weight Watchers tas part of a debt-heavy leveraged buyout. It took the company public in 2001, but held on to 51%.