Serena Williams is no stranger to brand deals. Courtesy Ro
Serena Williams, the tennis legend turned businesswoman, has taken on a new role as global ambassador for Ro, the telehealth company best known for its weight loss treatments, including the increasingly popular GLP-1 injections. The partnership marks a high-profile breakthrough for the booming weight loss sector—and a family affair. Williams’ husband, Reddit co-founder Alexis Ohanian, is an early investor in Ro and has served on the company’s board since 2018.
In a recent Ro commercial, Williams, 43, revealed that Ro helped her shed 31 pounds after giving birth to her second child. “They say GLP-1s for weight loss is a shortcut. It’s not, it’s science,” she said.
“I trained at the highest level, ate a clean diet, pushed myself, and still, after having kids, my body just wouldn’t respond,” she said in a statement. I realized it wasn’t about willpower; it was biological. My body needed the GLP-1 and clinical support.”
What is GLP-1, and how did Ro enter the scene?
Glucagon-like peptide-1 (GLP-1) drugs are a class of medications originally developed to treat Type 2 diabetes. They mimic a natural hormone that helps regulate blood sugar levels and, crucially, slow digestion—leading to reduced appetite and significant weight loss for many patients. They’ve gained widespread attention in recent years, with brand names like Ozempic, Wegovy and Zepbound driving record demand.
Initially, only Eli Lilly and Novo Nordisk were authorized to manufacture the key ingredients behind GLP-1s. But when demand surged beyond supply, both companies declared shortages with the FDA, opening the door for compounding pharmacies to enter the market. Even after supply normalized, the genie proved hard to put back in the bottle. Alternative manufacturers remain a growing force in the weight loss sector, even as Eli Lilly touts new clinical trial successes.
“I am expecting that in retrospect, both Novo and Eli Lilly probably wish they hadn’t reported the shortage,” Marta Wosinska, a health economist at the Brookings Institution, said last week on NPR’s Planet Money podcast.
Ro was founded in 2017 as Roman, a men’s health startup focused on treating erectile dysfunction. The company has since reinvented itself multiple times. Backed by early investors like General Catalyst, the company raised $3.1 million in seed funding before pulling in $88 million in a 2018 Series A.
That same year, the startup shortened its name to Ro, expanded into women’s health and added Ohanian to its board. By 2021, after several funding rounds, Ro hit a $5 billion valuation. In 2022, its reported valuation rose to $7 billion. The company entered the GLP-1 space in 2023, following the FDA’s approval of Zepbound, and has since made weight loss treatments one of its central offerings.
A cultural moment
For Ro—and for GLP-1s more broadly—the Williams partnership represents a cultural and commercial milestone. Celebrity endorsements of weight loss injections remain relatively rare. By sharing her experience, Williams placed herself at the center of a cultural moment where discussions about postpartum health, body image and medical interventions are increasingly mainstream. Besides Williams, Ro has also collaborated with retired basketball player Charles Barkley.
Williams herself is no stranger to brand deals. Although she earned nearly $95 million in prize money over her tennis career, much of her wealth (estimated at over $300 million) has come from endorsements. She has partnered with brands like Gatorade, JPMorgan Chase, Audemars Piguet and Beats by Dre.
She has also become an avid startup investor in recent years. Her investment firm, Serena Ventures, has backed 14 unicorn startups as of last year, including Noom, a Ro competitor offering weight loss and fitness services.
