Clair Health Unveils Wearable Technology for Continuous Reproductive Hormone Tracking

Founded by a team of Stanford University alumni, the startup Clair Health is pioneering a new frontier in women’s health with its wrist-worn device, Clair. This innovative wearable is engineered to provide continuous monitoring of four critical reproductive hormones: estrogen, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). By moving away from the traditional reliance on sporadic blood or urine tests, the device offers a real-time assessment of hormonal fluctuations, effectively addressing a long-standing diagnostic gap in the femtech industry.

The technical foundation of the Clair bracelet rests on a sophisticated array of ten integrated biosensors. These sensors capture a wide range of physiological metrics, including skin temperature, heart rate, heart rate variability (HRV), respiratory rate, and electrodermal activity, alongside comprehensive sleep and activity data. Proprietary machine learning algorithms then analyze this multimodal information to infer hormone levels, such as progesterone metabolites, through indirect physiological markers. Co-founder and CEO Jenny Duan highlights the necessity of this data, noting that women have historically navigated their health journeys "blindly." She compares the current lack of regular hormonal insights to the impossible task of managing diabetes without the ability to monitor blood glucose levels.

Clair Health is positioning its technology as a medical-grade solution, with the ultimate objective of securing clearance from the U.S. Food and Drug Administration (FDA). Unlike many existing consumer-grade cycle trackers that rely primarily on basal body temperature and calendar-based predictions, Clair aims to provide deep, dynamic hormonal insights. This level of precision is particularly vital for individuals managing Polycystic Ovary Syndrome (PCOS) or those with irregular menstrual cycles. The project’s scientific credibility is further bolstered by the involvement of Dr. Brindha Bavan, a clinical assistant professor at Stanford Medicine and a specialist in reproductive endocrinology.

To validate the accuracy of its hormonal inference models, the company is launching an independent clinical study at Stanford University. This research will involve approximately one hundred participants over several months, comparing the device’s "virtual" hormonal curves against gold-standard laboratory results. According to Dr. Bavan, such continuous monitoring is crucial for understanding the complex interplay between the pituitary gland and the ovaries, which dictates fertility, mental health, and overall physiological well-being. The company has set a clear roadmap for its rollout, with beta testing for the companion application scheduled for February 2026, followed by the initial shipment of devices in November of the same year.

The physiological inference approach championed by Clair Health represents a significant paradigm shift in personalized medicine. By making hormonal data as accessible as heart rate or sleep metrics, the startup is empowering users with unprecedented self-knowledge. Furthermore, the company’s commitment to local data processing aligns with modern digital privacy expectations. Beyond its primary focus on fertility, the wearable is designed to offer proactive insights into athletic performance, energy management, and the complex transition through perimenopause, ensuring a comprehensive approach to long-term wellness.