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Cycle and Ovulation
A science-backed approach to cycle and ovulation pattern tracking
Provides consistent, science-informed estimates of your ovulation and when it may or may not have happened.
Works for all types of cycles, from clockwork to unpredictable.
Estimates up to 12 cycles and track changes in ovulation and cycle health.
A complete view of your cycle health over time
Cycle Flags : Your cycle's quietest signals, decoded
Discover unique cycle patterns that help reveal hidden clues about your reproductive health
A comprehensive view of your cycle at every stage
How we compare
See how Cycle and Ovulation Plus compare with other traditional trackers in the market.
Cycle & Ovulation Plus
Others
| Cycle & Ovulation Plus | Others | |
|---|---|---|
| Period prediction | ||
| Ovulation phase estimation | ||
| plus exclusive Ovulation pattern estimation with 90%+ consistency |  | |
| plus exclusive Estimates possible non-ovulatory cycles | | |
| plus exclusive Support for irregular and diverse cycles | | |
| plus exclusive Cycle Flags, highlighting unique cycle patterns | | |
| plus exclusive Estimated your next 12 cycles | | |
| plus exclusive HSA/FSA eligibility | |
C&O 
Others
C&O  | Others | |
|---|---|---|
| Period prediction | ||
| Ovulation phase estimation | ||
| plus exclusive Ovulation pattern estimation with 90%+ consistency | | |
| plus exclusive Estimates possible non-ovulatory cycles | | |
| plus exclusive Support for irregular and diverse cycles | | |
| plus exclusive Cycle Flags, highlighting unique cycle patterns | | |
| plus exclusive Estimated your next 12 cycles | | |
| plus exclusive HSA/FSA eligibility | |
SCIENCE
Backed by research. Built for your cycle.
Impact of BMI, stress, and activity on menstrual cycle length and variability: insights from 4055 cycles of Ultrahuman Ring AIR users
How does heart rate and heart rate variability change over the day in men and women? A database analysis of Ultrahuman Ring AIR users
Modifying sleep tracking algorithms reveals specific sleep deprivation patterns in women: early findings from the Ultrahuman Ring AIR Ramadan Mode
Temperature-Derived Cycle Flags: Characterizing Menstrual Cycle Dynamics Using Ultrahuman Cycle Tracking & Ovulation (C&O Pro) Algorithm powered by OvuSense™
Listening In: Introducing the Ultrahuman Cycle Tracking & Ovulation Pro (C&O Pro) Feature Powered by OvuSense™
Your data is secure, private, and always under your control.
Start tracking your cycle today
Personalized insights for every phase of your cycle. Understand, optimize, and make informed choices.
Don’t have the Ring?
The Ultrahuman Ring tracks your fertility and cycle health with biomarkers like temperature, HRV, and RHR. Get yours to unlock the full suite of women’s health PowerPlugs.
Already have the Ring?
Great! Let’s set up your cycle tracking. Follow the link below to test it out and sync your ring for personalized insights.
Still got questions?
What is new in the C&O Plus PowerPlug compared to the previously available C&O PowerPlug?
C&O Plus builds on the capabilities of the original C&O PowerPlug by adding temperature-based cycle pattern recognition, Cycle Flags, and detailed cycle and fertility insights. While both versions offer cycle-phase estimation, C&O Plus goes further with:
- Support for irregular and diverse cycles
- Recognizes ovulation patterns with 90%+ consistency
- Highlights cycles without a clear ovulation pattern
- Cycle Flags to highlight key cycle patterns and possible variations
- Designed for wellness and fertility awareness use only – not a medical or diagnostic device
- Eligible for HSA/FSA benefits in the USA
These upgrades make C&O Plus especially valuable for users tracking fertility awareness in irregular cycles or observing pattern-based changes related to their overall wellness, while maintaining the consistency and privacy standards of Ultrahuman's ecosystem.
What is the difference between ovulation pattern recognition and fertility phase estimation?
Ovulation pattern recognition means observing a sustained temperature trend that suggests ovulation has occurred within a cycle.
Fertility phase estimation means highlighting the days when fertility-related patterns may be more likely to appear, based on your unique biomarker trends and past cycle data.
In short, estimation helps you understand potential fertile phases, while pattern recognition shows what your body experienced in that cycle. C&O Plus offers both to support cycle and fertility awareness.
Can I view or export my Cycle Report?
Yes — you can download a summary report of your past six cycles, showing patterns observed across temperature and fertility phases. A PDF export option is available so you can share your cycle trends with a healthcare professional. Your first report becomes available 30 days after activation.
Why does C&O Plus work for all kinds of cycles?
C&O Plus works effectively across a wide range of cycle types because its data model is built on a diverse set of real-world cycle patterns, including irregular, short, long, and variable cycles. This model is designed to observe temperature-based trends and adapt to your body's unique rhythm, rather than relying on fixed cycle lengths. By focusing on biometric patterns and consistency, C&O Plus helps you recognize fertility-related insights and cycle variations with awareness and confidence.
How is my data used to label Cycle Flags on my cycles?
The system analyses overnight temperature trends and other biomarker data recorded by Ring AIR to highlight consistent patterns in your cycle. Based on these trends, it applies Cycle Flags to reflect variations in fertility-related phases or temperature shifts, helping you understand your body's rhythm and cycle consistency.
The Ultrahuman Fertile Window feature provides educational information about menstrual cycle phases and potential fertility patterns to help women understand their body's natural rhythms. It is not intended for use as a contraceptive, a sole method to achieve pregnancy, a medical diagnostic tool, or a substitute for professional medical advice. Insights are based on individual biomarker patterns and statistical data, but cycle variations may occur, and actual fertility windows may differ. For medical advice, diagnosis, treatment, or guidance on fertility, conception, or contraception, consult a qualified healthcare provider.