We launched the Cycle and Ovulation PowerPlug in November 2024, and the response has been awe-inspiring.
Hundreds of thousands of women use Ultrahuman’s Cycle and Ovulation PowerPlug to take control of their health and fertility tracking, totally subscription-free.
The feedback from our community has been incredible, and we’ve listened. That’s why, just six months after its launch, we’re back with a major update that makes the Cycle and Ovulation algorithm 2.0 more accurate and adaptive.
Read on for how.
What’s new?
The Cycle and Ovulation algorithm 2.0 uses a ranking-based machine learning model to predict your ovulation window with far greater precision. It evaluates and ranks each day in your cycle by biological plausibility, based on temperature, HRV, and resting heart rate (RHR) deflection patterns.
Trained on more than half a million menstrual cycles from diverse cohorts, the model leverages population-level variance to boost accuracy for everyone.
We benchmarked its performance using LH-based ovulation predictor kits (OPKs) and validated against a clinically approved, medical-grade fertility device.
Key Improvements
More accurate predictions
The algorithm uses machine learning to analyze your previous cycles to make more accurate predictions. ML models can process huge amounts of data, and the more cycles you log, the more accurate the algorithm gets.
Period logging helps the algorithm learn about your unique cycle and provide fully personalized ovulation window prediction based on your biomarkers, as well as dates. You can start with just one cycle, but calibration takes three full cycles.
More in tune with your body right now
The updated algorithm puts extra weight on your recent cycle history. By focusing on recent cycles, as well as physiological patterns such as stress or disrupted sleep, the Cycle and Ovulation algorithm 2.0 improves the accuracy of ovulation predictions.
Analysis of user cycles showed significant variation in HR, temperature, and HRV patterns across cycles, driven by stress and sleep. Elevated cortisol levels blunt the LH/FSH surges needed for ovulation. This shows up in reduced estrogen, progesterone, and altered temperature and HRV patterns.
To address this, Cycle and Ovulation now enhances learning from recent intra-cycle data, making predictions more resilient to fluctuating stress and recovery states.
Less drift, more certainty
Because of the Cycle and Ovulation PowerPlug’s dynamic in-cycle prediction, changing biomarkers meant that the ovulation prediction window would sometimes shift.
We understand this can make users anxious. To address that, Cycle and Ovulation dynamically adjusts predictions in the early phase of your cycle, and locks the ovulation window once confidence passes a defined threshold. This ensures stability and consistency for our users.
We listened to our users to improve our algorithm and make Cycle and Ovulation more responsive, smarter, and even more aligned with real life.
Conclusion
With more focus on recent cycles, our predictions will account for life’s stress and strain more effectively, while also providing more certainty around your ovulation date.
The Cycle and Ovulation 2.0 algorithm is rolling out now. It will be applied from the start of your next cycle to avoid changes to your current predictions.
