Clair Health has raised $11.6 million in seed funding to build a continuous noninvasive hormone monitor for women, according to TNW. The round was led by Khosla Ventures, with participation from a16z speedrun, Brydge Club, Treehub, Cartan Capital, AGI House, Insiders VC, and 23andMe co-founder Anne Wojcicki.
The San Francisco-based startup was founded by Stanford graduates Jenny Duan and Abhinav Agarwal. Duan, who is 21, reportedly closed the funding round the same week she graduated from Stanford with a degree in symbolic systems. Agarwal previously helped develop a noninvasive continuous glucose monitor at KOS AI.
Clair Health plans to ship its wristband in November as a wellness product, with FDA clearance expected to follow later. The device is designed to help users track estrogen, progesterone, LH, and FSH through physiological signals rather than blood testing.
The wearable uses a stack of 10 biosensors, including biomagnetic sensors, to analyze signals such as skin temperature, heart rate variability, and electrodermal activity. Clair’s AI models then interpret those signals to infer where a user is in the hormonal cycle, using more than 130 proprietary biomarkers. The company also holds provisional patents on its sensor configuration.
Clair reports 94% accuracy in classifying menstrual cycle phases, benchmarked against daily urine samples rather than clinical blood analysis. An independent study through the Stanford Gladstone BeeHive program is underway, and the company plans to publish peer-reviewed results. However, peer-reviewed clinical data has not yet been published.
The startup also said it has trained AI to analyze voice-based biomarkers and determine cycle phase after a few minutes of conversation. Clair has already built a 25,000-person waitlist, sold out its presale, and received more than 100 letters of intent from fertility clinics.
Clair is entering a fast-growing women’s health and wearable technology market. The company’s longer-term roadmap includes perimenopause monitoring, hormone replacement therapy calibration, and diagnostics for conditions such as PCOS and endometriosis. Pricing has reportedly been cited at $369 for the device and $9.99 per month for the subscription.
The company said privacy is a key part of its approach, with data processed on the phone rather than in the cloud and protected through zero-knowledge encryption.
