Serena Williams showed off her slim figure in a bold swimsuit after revealing she’s been using a weight-loss medication. The athlete, 43, sported a bright yellow one-piece as she posed for a series of snaps Thursday. “melanin mellow-yellow ,” she captioned the Instagram carousel — and fans were quick to hype her up in the comments.

Tennis great Serena Williams has taken to social media to show off her dramatic recent weight loss wearing an ab-baring, two-piece gown, sports bras and tight baby T-shirts. But she is absolutely sizzling in a new share, showing her in the ocean in a tropical, bright yellow bathing suit with little cut-out.