The first smart ring built around the female cycle. Hormonal intelligence, fertility tracking, sleep optimization, and cardiovascular insights — personalized to where you are in your cycle, every single day.
Every feature in Bionic Eve is calibrated to the hormonal phases of the female body — not repurposed from a ring designed for men.
Bionic Eve learns your unique cycle from temperature, HRV, and resting heart rate patterns — predicting your next period, fertile window, and ovulation day with up to 94% accuracy. No manual input required.
HRV fluctuates significantly across the female cycle. Eve tracks your baseline for each phase so your readiness score is always accurate — not comparing follicular HRV to luteal HRV like a general-purpose ring would.
↑ HRV across 14-day window (follicular peak)
Eve identifies your fertile window up to 5 days in advance using the basal body temperature shift, HRV dip, and resting heart rate elevation pattern that occurs around ovulation.
Sleep architecture changes dramatically across the menstrual cycle. Eve provides phase-specific sleep recommendations — knowing that luteal phase sleep is lighter and more disrupted, and adjusting your coaching accordingly.
Continuous skin temperature measured to 0.1°C. The subtle rise after ovulation confirms the fertile window has closed. Early illness and inflammatory events are also detected before you feel symptoms.
Bionic Eve is calibrated to female cardiovascular norms, which differ meaningfully from male norms used in most wearables. Resting heart rate, VO₂ estimates, and arrhythmia thresholds all use female reference ranges validated in peer-reviewed clinical studies with female participants.
When Eve detects a potential pregnancy pattern (sustained temperature elevation + missed period), it shifts into Pregnancy Mode — adjusting all recommendations for a growing baby and tracking new relevant metrics like resting heart rate elevation and sleep position time.
Eve recognises the HRV signature of luteal-phase hormonal stress and PMS onset — giving you a heads-up 48 hours before mood changes typically arrive, so you can plan your most demanding work and social obligations accordingly.
Every algorithm in Bionic Eve was trained on datasets that include female participants — unlike most wearable AI trained predominantly on male data.
Four finishes, each in titanium. Each in sizes 4–12. Each under 2.8mm thin and 3.2g light.
I've been tracking my cycle with apps for 5 years. Bionic Eve showed me I was ovulating 3 days earlier than I thought — every month. That's the kind of precision that actually matters when you're trying to conceive.
The PMS alert is uncanny. It told me 2 days before my mood shift that my luteal stress pattern was elevated and to 'protect your schedule.' I cancelled two meetings and had my best week at work in months.
As a sports physician, I've recommended cycle-aware training to athletes for years. Bionic Eve is the first consumer device that actually gets the science right. The female-calibrated HRV alone is worth the price.
Free shipping worldwide · FSA/HSA eligible · Financing from $29/mo · 30-day returns
Also available on Bionic Adam → for him