Serena Williams is showing off her 31-pound weight loss after going on the GLP-1 medication Ro.

“I feel great,” Williams, 43, told People in an interview published on Thursday, August 21. “I feel really good and healthy. I feel light physically and light mentally.”

The retired tennis pro explained that she decided to try weight-loss medication because she was “never” able to reach the weight she “needed” after giving birth to daughter Olympia in 2017.

“It was crazy because I’d never been in a place like that in my life where I worked so hard, ate so healthy and could never get down to where I needed to be at,” she recalled. “I had never taken shortcuts in my career and always worked really hard. I know what it takes to be the best.”

As a result, it was “very frustrating” for Williams to continue working hard and not seeing results.

Williams shares Olympia with husband Alexis Ohanian. The couple expanded their family with their second daughter, Adira, in August 2023. After giving birth a second time, Williams had a similar experience with her weight. At first, she was able to drop some baby weight, but after two weeks, the number didn’t change.

“I never lost another pound,” she told People. “I just thought, gosh, I don’t know if I would ever be able to get back to where I needed to get to.”

Then, she started researching Ro, wondering if the GLP-1 was a “shortcut” for her weight loss. (Williams started the injections in early 2024, after she stopped breastfeeding Adira. She told Today on Thursday that she was initially “on and off” the medication before going all in.)

“I really wanted to dive into it before I just did it,” she said, noting that she never “felt that pressure” to maintain a certain body image but didn’t feel like herself with the extra weight. (Williams also told Today that she didn’t get any side effects from the medication.)

Rosie O’Donnell surprised fans in May 2025 by revealing a positive update on her weight loss journey — which she credited to using the medication Mounjaro. The injectable drug (also known as tirzepatide) is similar to Ozempic and Wegovy in that it is used primarily to treat diabetes, but can also be effective in weight […]

“The size I was before, there was nothing wrong with it. It’s just not what I wanted to have,” Williams said. “I just knew that I wanted to be where I personally felt comfortable.”

Williams is the latest celebrity to share their success with GLP-1s. Other stars have boasted about their weight loss after using Ozempic or Mounjaro, which is the same type of medication.

Not only did the GLP-1 make her look better — she’s been showing off her new body in a several Instagram photos — but Williams told the publication that she feels better as well.

“I’m more active. My joints don’t hurt as much. I just feel like something as simple as just getting down is a lot easier for me. And I do it a lot faster,” she said. “I feel like I have a lot of energy and it’s great. I just feel pretty good about it.”