Clair Health Raises $11.6M for Continuous Hormone-Tracking Wearable

Two Stanford grads in their 20s have created a wearable to give women’s hormones the kind of continuous tracking sleep already gets

Clair Health, a jewelry-inspired wearable startup, has closed $11.6M to build what it calls the first noninvasive wearable that continuously tracks women’s hormones. 

The round, led by Khosla Ventures, lands months ahead of the company’s November product launch.

The fresh capital will also feed Clair’s research, which has already yielded a device that it says reads estrogen, progesterone, LH (luteinizing hormone) and FSH (follicle-stimulating hormone) using 10 biosensors and more than 130 proprietary biomarkers, without blood draws or urine tests.

Andreessen Horowitz’s startup accelerator a16z speedrun also joined the round, along with Brydge Club, AI in Health Fund, Cartan Capital, AGI House, Insiders VC and Anne Wojcicki.

Clair says its waitlist tops 25,000 and that its first run of 5,000 units sold out six months before release.

Though wearables track heart rate variability, sleep, step count and breathing rate well, they have missed that all of those signals in women are shaped by hormones, Clair co-founder Jenny Duan said.

In beta, the company says it has identified 9 sub-phases of the menstrual cycle, more than double the four women are typically taught. The device targets everything from fertility and conception timing to hormonal conditions such as PCOS, athletic recovery and perimenopause, as well as the

“The data has always been there; we just haven’t had something to read it until now,” Duan said. “What we’re building will shape how we interpret women’s health and support the overall well-being of women.”

Clair is launching into a crowded U.S. market and one that is more health-engaged than before. According to Rock Health’s 2025 Consumer Adoption Survey, 57% of Americans now own a wearable or connected device, and first-time buyers are getting harder to find.