The science behind your cycle.
Guides on menstrual health, biometrics, and how your body works across every phase.
Estrogen explained: the hormone that drives the first half of your cycle
Estrogen rises through the follicular phase, helps trigger ovulation, and affects the brain, bones, heart, and mood. Learn how it changes across the cycle.
Mood changes across your menstrual cycle: what's normal
Hormonal shifts can affect mood across the menstrual cycle. Learn what may happen in each phase, how PMS and PMDD differ, and how to track your own pattern.
Period pain relief: what the evidence supports
Period cramps affect most menstruating people, but remedies vary in effectiveness. Learn what clinical evidence says about treating dysmenorrhea.
How Resting Heart Rate Changes Across Your Cycle
Resting heart rate is generally lower in the follicular phase and higher in the luteal phase. Learn why it changes and how to read your own pattern.
Progesterone and the luteal phase
Progesterone rises after ovulation and shapes the second half of the menstrual cycle. Learn what it does and what low levels may mean.
How Your Cycle Changes in Your 30s and 40s
Menstrual cycles don't stay the same forever. Learn how age, declining ovarian reserve, and perimenopause change your cycle length, symptoms, and biometric patterns.
What Happens During Your Period? The Menstrual Phase Explained
A period marks the start of a new hormonal cycle. Learn what happens during menstruation and what common symptoms can mean.
Cycle Syncing Your Nutrition: What the Science Says
Research on cycle-based nutrition shows modest changes in nutritional needs, cravings, and metabolism across the menstrual cycle.
How Hormonal Birth Control Changes Your Cycle
Hormonal contraceptives suppress ovulation and replace the natural cycle with a synthetic one. The pill, IUD, and implant affect hormones, biometrics, and cycle phases in different ways.
Why Your Energy Levels Change Throughout Your Cycle
Energy highs and lows across the month can follow hormonal shifts in each cycle phase. The pattern varies, but research and wearable data can help make sense of it.
How Stress Affects Your Menstrual Cycle
Chronic stress can delay ovulation, shorten your luteal phase, or cause missed periods entirely. Learn the science behind the stress-cycle connection and what your body is telling you.
What Happens During the Follicular Phase?
The follicular phase is when your body prepares for ovulation. Learn how hormones change, how long the phase lasts, and why its length can vary.
Track your cycle with real body data.
Ovuly uses your Apple Watch signals — HRV, wrist temperature, sleep — to help you understand your cycle beyond calendar predictions.