Luteal phase: definition and meaning
The luteal phase is the second half of the menstrual cycle, from the day after ovulation until the day before your next period. It usually lasts 12 to 14 days. During it, the corpus luteum makes progesterone to prepare the uterus for a possible pregnancy. If no pregnancy happens, hormones fall and a period begins.
What happens in the luteal phase
After ovulation, the empty follicle becomes the corpus luteum. It makes progesterone and some estrogen, which thicken the uterine lining and raise your resting temperature slightly. If an egg implants, hCG keeps the corpus luteum going. If not, it shrinks after about 10 to 14 days, hormones drop, and your period starts.
Why the luteal phase matters for mood
This is where PMS lives. The fall in progesterone and estrogen in the last days of the phase seems to affect serotonin in people who are sensitive to it, which can bring irritability, tears, anxiety, cravings and poor sleep. Knowing your luteal days are coming makes them easier to plan around.
- Early luteal: often calm, steady, a little sleepy
- Mid luteal: progesterone peaks, appetite may rise
- Late luteal: hormones drop, PMS symptoms are most likely
Read the full guide to the luteal phase, or see premenstrual syndrome and luteal phase defect.
Frequently asked questions
Is the luteal phase always 14 days?
No. Anything from about 10 to 16 days is common. It tends to be more stable than the first half of the cycle, which is why cycle length differences usually come from the follicular phase.
Can I calculate my luteal phase?
Yes: count from the day after ovulation to the day before your period. Our luteal phase calculator does it for you.
Why do I feel so tired in the luteal phase?
Progesterone has a mildly sedating effect and raises your body temperature slightly, which can affect sleep. Many people feel sleepier and hungrier in this phase, especially in the last week before their period.
Sources
- Cleveland Clinic: Menstrual Cycle
- Office on Women's Health: Your menstrual cycle
- ACOG: Premenstrual Syndrome (PMS)
This page is for information only and isn’t medical advice. If something worries you, please talk to a doctor.
Keep reading
Luteal phase: why feelings get louderWhat the luteal phase is, how long it lasts, why progesterone rises and falls, and the common symptoms: PMS, cravings, low energy and mood changes.
Progesterone: definition and meaningProgesterone is the hormone made after ovulation that prepares the uterus for pregnancy. Its role in the luteal phase, PMS, mood, sleep and temperature.
Corpus luteum: definition and meaningThe corpus luteum is the temporary gland left after ovulation that makes progesterone. What it does, how long it lasts, and how it shapes your luteal phase.Luteal phase calculator: how long is my luteal phase?Free luteal phase calculator: enter your ovulation day and next period to see your luteal phase length and whether it sits in the typical 11 to 17 day range.
Luteal phase mood: a kind survival guideWhy the luteal phase can bring anxiety, low mood, irritability and tears, when it usually starts, what actually helps, and when it might be PMDD.