TL;DRClair Health raised $11.6M from Khosla Ventures for a noninvasive wearable hormone monitor. It ships in November but has no peer-reviewed results yet.
Clair Health, a San Francisco startup founded by two Stanford graduates, has raised $11.6 million in seed funding to build what it calls the first continuous, noninvasive hormone monitor for women. Khosla Ventures led the round, with participation from a16z speedrun, Brydge Club, Treehub, Cartan Capital, AGI House, Insiders VC, and 23andMe co-founder Anne Wojcicki. The company plans to ship the wristband in November as a wellness product, with FDA clearance to follow later.
Co-founder Jenny Duan, 21, closed the round the same week she graduated from Stanford with a degree in symbolic systems, according to Fortune. She started the company with Abhinav Agarwal after the two met at Stanford in spring 2025. Agarwal previously helped develop a noninvasive continuous glucose monitor at KOS AI.
The device uses a stack of 10 biosensors, including biomagnetic sensors that Clair says are not found in any competing consumer wearable, to read physiological signals like skin temperature, heart rate variability, and electrodermal activity. AI models then interpret those signals to infer where a woman is in her hormonal cycle, tracking estrogen, progesterone, LH, and FSH across more than 130 proprietary biomarkers. The company holds provisional patents on the sensor configuration.
