Launching Fall 2026 on the App Store
Finally understand why you feel this way.
Reen connects your cycle, symptoms, wearables, and labs into one clear picture of your hormonal health. Be one of the first users.
Join the waitlistToday
Cycle day 21
How do you feel?
Your cycle report
Day 17 to 28
Fatigue by cycle day
Pattern found
Fatigue peaks in your luteal phase
What if your health was...
Understood
Your symptoms are signals. Reen connects them into patterns.
Women wait years for answers. Symptoms get dismissed, data gets scattered, and conditions like PCOS and endometriosis take close to a decade to diagnose.
1 in 5
US women are unable to get pregnant after a year of trying (CDC)
11 years
Average wait for an endometriosis diagnosis in the US
40%
Of women report being misdiagnosed when seeking perimenopause care
110,000+
New US gynecologic cancer cases expected each year
Precision medicine. Personal results.
Undiagnosed Symptoms
We decode chronic pelvic pain, painful periods, irregular bleeding, digestive and urinary tract issues with precision risk scores for gynecological conditions like endometriosis and PCOS.
Perimenopause & Menopause
Get your perimenopause stage, symptom forecasting, personalized HRT guidance, and whole-body aging insights. No more guessing.
Fertility & Reproductive Health
Reproductive age, miscarriage risk, genetic factors, and nutrient deficiencies, with personalized egg preservation timeline and IVF insights.
Gynecological Cancer Risk
Comprehensive cancer risk assessment analyzes genetic predispositions, hormonal patterns, and inflammatory markers for early detection and prevention.
The science
Better Data Collection
Comprehensive self-reported symptoms, cycle data, lab results, and doctor visit notes: the information traditional care overlooks.
Our Own Medical Knowledge Engine
We built Reen's AI on our own medical knowledge engine: every answer is grounded in peer-reviewed research and your own tracked data, not generic internet text.
Wearable Integration
Passively sync Apple Health, Oura Ring, and Whoop: HRV, sleep, temperature, and recovery data feed your health picture automatically.
Longitudinal Tracking
Continuous data collection reveals how your health changes over time, catching shifts before symptoms appear.
Holistic Integration
Your body is an interconnected network. Reen integrates many layers of information into one complete picture.
Risk Insights + Action Plan
Predictive models identify early warning signs and personalize care based on your unique risk profile.
Reen informs and prepares. It never diagnoses.
Everything you need, in one place
Five powerful tabs designed to help you track, understand, and take control of your hormonal health.
Your daily dashboard
Home
Cycle day tracking, health metrics, readiness insights, and symptom logging, all at a glance.
Log everything that matters
Track
Period flow, symptoms, medications, mood, and energy, beautifully organized and effortless to use.
See the patterns
Insights
AI-powered health overview, cycle trends, symptom frequency analysis, and lab result tracking.
Clinical-grade summaries
Reports
Generate HIPAA-compliant health reports for your doctor with one tap. Your data, professionally presented.
Knowledge library
Learn
Curated clinical insights on endometriosis, PCOS, perimenopause, HRT, thyroid health, and more.
Why I built Reen
Before I was an engineer, I was a nurse. I worked in oncology medicine for several years. I went on to study data science and AI at Harvard to become a machine learning engineer, and Reen is where those two lives meet: using AI and real data so more women can understand their health, advocate for themselves, and reach diagnoses and treatment faster.
This app is named after my grandma, Noreen ♥
Mikaela
Founder of Reen
Join the waitlist
Reen launches Fall 2026 on the App Store. Sign up and be one of the first users when it arrives.