The luteal phase is the second half of your menstrual cycle, starting right after ovulation and ending when your period begins. It lasts 12 to 14 days on average, though anywhere from 10 to 17 days is considered normal. During this stretch, your body prepares the uterus for a possible pregnancy, and if one doesn’t happen, the phase ends with menstruation.
What Happens Inside Your Body
When your ovary releases an egg at ovulation, the empty follicle it came from doesn’t just disappear. The cells that made up that follicle transform into a new, temporary structure: a small yellowish mass that starts producing progesterone. This structure is the engine of the entire luteal phase.
Progesterone’s main job is to thicken and enrich the uterine lining so it can support a fertilized egg. Think of it as your body optimistically preparing a nursery every single cycle. Estrogen also rises during this phase, working alongside progesterone to maintain that lining.
If fertilization doesn’t occur, the temporary structure in your ovary breaks down around day 10 to 12 after ovulation. Progesterone and estrogen levels drop sharply, the thickened uterine lining can no longer sustain itself, and it sheds. That’s your period, and it marks the end of the luteal phase.
What Happens If You Get Pregnant
If a fertilized egg implants in the uterine lining, it begins releasing a hormone (the one pregnancy tests detect) that sends a rescue signal to the progesterone-producing structure in your ovary. Instead of breaking down, it keeps functioning and continues pumping out progesterone to sustain the pregnancy. This keeps the uterine lining intact and nourished. Eventually, the placenta takes over progesterone production, but for the first several weeks, your body depends on that small ovarian structure to hold everything together.
Common Symptoms During This Phase
Rising progesterone doesn’t just affect your uterus. It interacts with brain chemicals that regulate mood, particularly serotonin. This is why many people notice mood swings, irritability, anxiety, or feeling unusually emotional in the days after ovulation. For some, progesterone has a calming, sedating effect. For others, it does the opposite.
Physical symptoms are common too. Breast tenderness and bloating are among the most frequently reported. Fatigue and sleep disturbances often show up because progesterone can make you feel drowsier during the day while simultaneously disrupting nighttime sleep quality. These symptoms overlap heavily with what’s commonly called PMS, which is really just a label for the more noticeable end of the luteal phase symptom spectrum.
Skin Changes and Breakouts
If you tend to break out at the same point in your cycle, the luteal phase is likely responsible. Progesterone causes skin to swell slightly and pores to tighten, which traps oil underneath the surface. Then, as progesterone drops in the final days before your period, androgens (hormones that stimulate oil production) become relatively more dominant. The result is increased oil production hitting already-clogged pores, which is why hormonal acne tends to peak right before or at the start of menstruation.
Your Metabolism Shifts Slightly
You may have heard that your body burns more calories during the luteal phase. There’s truth to this, but the effect is modest. A 2026 systematic review in Frontiers in Physiology found that resting metabolic rate tends to increase during this phase, but the bump is roughly 30 to 120 extra calories per day, which works out to about a 3 to 5 percent increase. The simultaneous peak in estrogen and progesterone during the mid-luteal phase is thought to drive this uptick in energy expenditure. It’s real, but it’s small enough to overlap with normal day-to-day variation in how many calories your body burns at rest.
That said, it may explain why some people feel hungrier in the second half of their cycle. Your body is genuinely using a bit more energy.
When the Luteal Phase Is Too Short
A luteal phase that consistently lasts 10 days or fewer is considered a luteal phase deficiency. The concern is straightforward: if this phase is too short, progesterone doesn’t have enough time to properly prepare the uterine lining. Even if an egg gets fertilized, it may not have a suitable environment to implant in.
The American Society for Reproductive Medicine defines this condition as a luteal phase of 10 days or less, sometimes combined with low progesterone levels during the middle of the phase. In normal ovulatory cycles, about 31 percent of the time progesterone stays below the levels some researchers consider ideal for supporting implantation. This means luteal phase issues are more common than many people realize and can be a contributing factor in difficulty getting pregnant or recurrent early pregnancy loss.
If you’re tracking your cycle and consistently see fewer than 10 days between ovulation and your period, that’s worth bringing up with a healthcare provider, especially if you’re trying to conceive.
How to Know When You’re in It
Unless you’re tracking ovulation (through basal body temperature, ovulation predictor kits, or cervical mucus changes), you won’t know the exact day your luteal phase starts. But you can work backward. If your cycle is 28 days, ovulation typically happens around day 14, making days 15 through 28 your luteal phase. If your cycle is shorter or longer, the follicular phase (the first half) is usually what varies. The luteal phase tends to stay relatively consistent from cycle to cycle for the same person, which is why it’s useful for predicting when your period will arrive once you know when you ovulated.