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The four phases of the menstrual cycle
What happens in the menstrual, follicular, ovulation and luteal phases, how long a normal cycle is, and how each phase can affect energy and mood.
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In short
The four phases of the menstrual cycle
The menstrual cycle has four phases: menstruation (your period), the follicular phase, ovulation and the luteal phase. A cycle is counted from the first day of one period to the first day of the next, and for adults it usually lasts 21 to 35 days. Hormone changes across the phases can shift your energy, mood, sleep and appetite.
Written by the Gyne team · Medical review: pending
Key takeaways
- A cycle starts on the first day of your period and usually lasts 21 to 35 days in adults.
- Ovulation usually happens about 14 days before your next period, not always on day 14.
- The luteal phase is the most stable in length; the follicular phase varies most.
- Tracking your own cycle shows your patterns better than any average.
What happens during your period?
Day 1 of your cycle is the first day of full bleeding. If you're not pregnant, the lining of the uterus sheds. A period usually lasts 2 to 7 days.
Estrogen and progesterone are at their lowest, which is why some people feel tired or low at the start of their period. Cramps are common and usually ease after a day or two.
What is the follicular phase?
The follicular phase starts on day 1 too and lasts until ovulation. The brain releases follicle-stimulating hormone (FSH), which helps eggs in the ovaries mature.
Estrogen rises through this phase and the lining of the uterus thickens again. Many people notice more energy and a better mood as estrogen climbs. This phase is the part of the cycle that varies most in length, which is why cycle lengths differ.
When does ovulation happen?
Ovulation is when an ovary releases an egg. A surge of luteinizing hormone (LH) triggers it, and it usually happens about 12 to 16 days before your next period.
Around ovulation, cervical mucus often becomes clear, slippery and stretchy, like raw egg white. Some people feel a twinge on one side of the lower belly. You can get pregnant from sex in the five days before ovulation and on the day itself.
What is the luteal phase?
After ovulation, the empty follicle becomes the corpus luteum and makes progesterone, which prepares the uterus for a possible pregnancy. This phase usually lasts 11 to 17 days and is fairly steady from cycle to cycle.
Progesterone raises your body temperature slightly. If you're not pregnant, hormone levels fall at the end of this phase and your period starts. Premenstrual symptoms like bloating, sore breasts, cravings and mood changes are common in the last days.
What is a normal cycle?
For adults, a cycle of 21 to 35 days is usual. In the first years after periods start, cycles can range from 21 to 45 days. It's normal for your cycle to vary by a few days from month to month.
When to see a doctor
- Your periods stop for more than three months and you're not pregnant.
- Your cycles are often shorter than 21 days or longer than 35 days (45 for teens).
- You bleed for more than 7 days, soak a pad or tampon every hour, or pass large clots.
- You bleed between periods, after sex or after menopause.
- Period pain stops you from doing everyday things.
How Gyne helps
Gyne shows where you are in your cycle and what your phase usually means for energy, mood, hunger and workouts. It learns your own rhythm as you log and predicts your next period as a range.
PeriodsThis guide is general information, not medical advice. Only a doctor can diagnose a condition.