Announcing our latest round led by Khosla Ventures

The first wearable for hormone-aware health

Understandyour body

like neverbefore

For every stage of your life

More energy today?Your hormone trends suggest you’re approaching ovulation.

Clair continuous hormone monitor sensor stack

ClairStackTM

Trained on clinical data from

100,000+

women

Developed with leading scientists

Emily Kraus, MD

Clinical Assistant Professor

Clinical Assistant Professor at Stanford in sports medicine and women’s health. U.S. Olympic Women’s Health Task Force member.

Sara Vaughn, MD

Chief Medical Officer

Board-certified reproductive endocrinologist. Former Stanford physician advancing innovation in fertility and women’s health.

Roxana Daneshjou, MD, PhD

Advisor

Stanford assistant professor and developing AI for healthcare. Leader in precision medicine and responsible AI in clinical care.

How does Clair work?

Hormones produce measurable physiological effects across your body, continuously. Progesterone raises your body temperature, shifts your heart rate, and alters your sleep architecture. Estrogen modulates cardiovascular tone and heart rate variability. Clair's multi-modal sensor array captures over 130 biomarkers spanning cardiovascular, thermoregulatory, autonomic, electrodermal, and other domains, then uses machine learning models trained against hormone measurements to decode the combined pattern into physiological hormonal insights.

What all does Clair track?

Clair is a full-stack wellness wearable that captures sleep, recovery, daily activity, heart rate, HRV, and performance metrics. Most women juggle three separate workflows to see this picture: a calendar app for cycle, at-home urine sticks for hormones, and fitness wearables for everything else. Clair collapses all three into one app, with the cycle as the primary signal.

How does Clair compare with other wearables?

A woman's HRV dropping 12% in her luteal phase looks like a recovery problem to a fitness algorithm. Clair was built from the ground up to treat female hormonal physiology as the primary signal. We use proprietary sensing modalities and train models on paired wearable-and-hormone data to decode what your body is actually telling you.

What clinical evidence supports Clair?

Clair was validated against at-home urine tests. We are launching several studies including one through the Stanford Gladstone BeeHive Initiative to train and validate our production hardware.

Does Clair work for women with irregular cycles?

Unlike calendar-based predictions, Clair tracks your actual cycle as it unfolds by monitoring real-time physiological signals.