--- title: Corpus luteum: what it is and why it matters for PMS description: The corpus luteum is a temporary gland that forms after ovulation and makes progesterone, and its breakdown helps trigger PMS and PMDD symptoms. url: https://niyora.com/glossary/corpus-luteum/ --- - [Niyora](https://niyora.com/) - [Glossary](https://niyora.com/glossary/) - Corpus luteum: what it means Term # Corpus luteum: what it means The corpus luteum is the temporary gland your ovary forms right after releasing an egg, and it's the main source of progesterone in the second half of your cycle. It also produces the calming hormone allopregnanolone. When it breaks down about two weeks after ovulation, progesterone and allopregnanolone drop fast, a shift that triggers PMS and, in some people, PMDD symptoms. Updated 13 October 2026 Niyora editorial ## At a glance - The corpus luteum forms from the ruptured ovarian follicle right after ovulation and stays active for about two weeks. - It's the main source of progesterone, and some estrogen, in the second half of the menstrual cycle. - Progesterone from the corpus luteum converts into allopregnanolone, a calming brain chemical that rises and falls with it. - When the corpus luteum breaks down, progesterone and allopregnanolone drop fast, a shift linked to PMS and PMDD symptoms. - PMDD reflects a different reaction to this normal hormone drop, not abnormal hormone levels. ## What is the corpus luteum? The corpus luteum is a small, temporary gland. After an ovary releases an egg during ovulation, the empty follicle that held the egg transforms into this new structure, named for its yellow color (corpus luteum means "yellow body" in Latin). Its job is to make progesterone, and some estrogen, for roughly two weeks. That hormone support keeps the uterine lining ready in case the egg is fertilized. A 1987 study that gave women a GnRH injection at different points in the luteal phase found no steroid response in the earliest days after ovulation, but a significant progesterone and estradiol response by the mid-luteal phase that held through the late luteal phase, though it became inconsistent in the two days right before a period (Journal of Clinical Endocrinology and Metabolism, 1987). If no pregnancy happens, the corpus luteum breaks down near the end of the luteal phase. Progesterone and estrogen fall with it, and that drop is what brings on a period, along with many premenstrual symptoms. You can read more about how these hormone shifts play out across the month in [the luteal phase: what's happening in your body and mood](https://niyora.com/luteal-phase/). ## How does the corpus luteum relate to PMS and PMDD? The corpus luteum's progesterone also gets converted into allopregnanolone, a calming compound that acts on the brain's GABA receptors, similar to how some anti-anxiety medications work. Allopregnanolone rises and falls along with the corpus luteum's lifespan, climbing through the luteal phase and dropping fast once the gland breaks down. PMDD is a different reaction to this normal hormone shift, not a sign that hormone levels themselves are abnormal (Schmidt et al., 1998, NEJM; Dubey et al., 2017, Molecular Psychiatry). A trial that blocked the enzyme converting progesterone into allopregnanolone found that, at a high enough dose, this eased core PMDD symptoms including irritability, sadness, and anxiety (Neuropsychopharmacology, 2016). That result points to the corpus luteum's hormone output, and how the brain responds to it, as a real driver of premenstrual symptoms. For more on how this fits into PMDD, see [PMDD (premenstrual dysphoric disorder), explained](https://niyora.com/pmdd/) and [what causes PMDD](https://niyora.com/questions/what-causes-pmdd/). The calming hormone itself has its own entry at [allopregnanolone: what it means](https://niyora.com/glossary/allopregnanolone/). ## Why does the corpus luteum matter for treatment or coping? Because the corpus luteum is only active in the second half of the cycle, several PMDD treatments are timed to match it. In placebo-controlled trials, luteal-phase-only dosing of citalopram (Journal of Clinical Psychopharmacology, 1998), sertraline (Journal of Clinical Psychiatry, 1998), and clomipramine (Neuropsychopharmacology, 1993) reduced PMDD symptoms more than placebo, and so did continuous daily fluoxetine (Journal of Clinical Psychiatry, 1991). A doctor decides whether luteal-phase-only dosing, continuous dosing, or another option fits you. None of that means you have to wait out two weeks before getting relief in the moment. If a fight or a wave of tears catches you while your corpus luteum is still active and hormones are shifting, having somewhere to put it helps. Niyora is a PMS and PMDD support app. Its Moon feature lets you write down what happened, see it from another angle, calm down, and draft a reply you can hold onto before you send anything. When to see a doctor If premenstrual symptoms take up a week of every month, or you're having thoughts of hurting yourself, see a GP or gynecologist and bring two months of daily notes. ## What related terms should you know? A few related terms show up alongside corpus luteum in cycle tracking and research: - **Luteal phase**: the second half of the cycle, from ovulation to the day before your period, named for the corpus luteum that's active during it. - **Allopregnanolone**: the calming brain chemical made from the progesterone the corpus luteum produces. Read [allopregnanolone: what it means](https://niyora.com/glossary/allopregnanolone/). - **PMDD**: the diagnosis some people get when their reaction to the corpus luteum's hormone swings causes severe mood symptoms, covered in full at [PMDD (premenstrual dysphoric disorder), explained](https://niyora.com/pmdd/). - **Dysmenorrhea**: period pain, a separate issue from PMDD that can also show up once the corpus luteum breaks down and progesterone drops. See [dysmenorrhea vs PMDD: what it means](https://niyora.com/glossary/dysmenorrhea/). If one of these terms sounds like your own pattern, Niyora's Moon can help you track it day by day. ## Questions people ask What does the corpus luteum do? + The corpus luteum is a temporary gland that forms after ovulation. It produces the progesterone, and some estrogen, that support the second half of the menstrual cycle, and that progesterone converts into allopregnanolone, a calming brain chemical. When the corpus luteum breaks down, both hormones fall fast, which helps trigger a period. How long does the corpus luteum last? + The corpus luteum typically stays active for about two weeks, covering the luteal phase from ovulation to the day before your period. If pregnancy happens, it keeps producing progesterone until the placenta can take over that job later in the first trimester. Does the corpus luteum cause PMDD? + The corpus luteum doesn't cause PMDD by producing abnormal hormone levels. Research points to PMDD being a different brain reaction to the normal hormone drop that happens when the corpus luteum breaks down, not a problem with the hormones themselves (Schmidt et al., 1998; Dubey et al., 2017). Can the corpus luteum affect your mood before your period? + Yes. As the corpus luteum ages, it changes how much progesterone and allopregnanolone it releases, and that shift affects mood for many people. Most notice mild changes that ease once a period starts. A smaller group has a stronger reaction that fits a PMDD pattern. ## Sources - 1. [5α-Reductase Inhibition Prevents the Luteal Phase Increase in Plasma Allopregnanolone Levels and Mitigates Symptoms in Women with Premenstrual Dysphoric Disorder](https://doi.org/10.1038/npp.2015.246), Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 2016 - 2. [Luteal responses to gonadotropin-releasing hormone during the luteal phase: relation to the age of corpus luteum](https://doi.org/10.1210/jcem-64-2-274), The Journal of clinical endocrinology and metabolism, 1987 - 3. [Citalopram in premenstrual dysphoria: is intermittent treatment during luteal phases more effective than continuous medication throughout the menstrual cycle?](https://doi.org/10.1097/00004714-199810000-00007), Journal of clinical psychopharmacology, 1998 - 4. [Clomipramine administered during the luteal phase reduces the symptoms of premenstrual syndrome: a placebo-controlled trial](https://doi.org/10.1038/npp.1993.52), Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 1993 - 5. [Treatment of premenstrual dysphoric disorder with sertraline during the luteal phase: a randomized, double-blind, placebo-controlled crossover trial](https://doi.org/10.4088/jcp.v59n0206), The Journal of clinical psychiatry, 1998 - 6. [Fluoxetine in the treatment of late luteal phase dysphoric disorder](https://pubmed.ncbi.nlm.nih.gov/2071558/), The Journal of clinical psychiatry, 1991 Ask AI about this page Copy prompt ChatGPT ↗ Claude ↗ Perplexity ↗ Google AI Mode ↗ Grok ↗ On this page - [What is the corpus luteum?](#what-is-the-corpus-luteum) - [How does the corpus luteum relate to PMS and PMDD?](#how-does-the-corpus-luteum-relate-to-pms-and-pmdd) - [Why does the corpus luteum matter for treatment or coping?](#why-does-the-corpus-luteum-matter-for-treatment-or-coping) - [What related terms should you know?](#what-related-terms-should-you-know) - [Questions](#faq) Niyora PMS & PMDD support For the hard moment before your period. Private, no account. [Get it on iPhone](https://apps.apple.com/app/niyora-pms-emotions/id6764561688) ## Keep reading Condition PMDD (premenstrual dysphoric disorder), explained Condition The luteal phase: what's happening in your body and mood Question What causes PMDD? Cycle guide Menstrual cycle hormones, phase by phase Guide All 26 findings, graded Term What Does PMS Mean in Text and Slang?