Last checked September 2026 against 21 sources · Editorial policy
Progesterone: what it does for women
Progesterone is a hormone made mainly by the ovaries after ovulation, by a temporary gland called the corpus luteum. It prepares the uterine lining for a fertilized egg; if pregnancy doesn't happen, progesterone falls and your period starts. In pregnancy it keeps rising, and the placenta takes over making it. In perimenopause, more cycles skip ovulation, so progesterone often drops before estrogen does.
Progesterone prepares the uterine lining, supports pregnancy and may aid sleep. It often falls first in perimenopause. What it does, normal levels, low-level signs.
Progesterone: expectation vs reality
What people often expect
“Progesterone only matters if you're trying to get pregnant”
What the evidence shows
Progesterone also keeps estrogen from overgrowing the uterine lining, which is why anyone with a uterus who takes estrogen for menopause also needs a progestogen. It affects sleep too: in a small trial, 300 mg at bedtime cut time awake during disturbed nights by 53%, and in another it reduced hot flash scores in early postmenopause.
What progesterone does in the body
What does progesterone do for women?
Its main job is to prepare the lining of the uterus for a fertilized egg to implant and grow. It also regulates bleeding during your period, supports an early pregnancy, prevents ovulation and uterine contractions during pregnancy, and prepares the breasts for breastfeeding. Cleveland Clinic also lists effects on mood and thyroid function. The adrenal glands make small amounts too.
Progesterone in the menstrual cycle
After ovulation, the empty egg follicle becomes the corpus luteum, which makes progesterone and thickens the uterine lining. If no egg is fertilized, the corpus luteum breaks down, progesterone falls, and the lining sheds as your period. Labcorp's range is 0.1 to 0.9 ng/mL before ovulation and 1.8 to 23.9 ng/mL in the luteal phase, the second half of the cycle.
Learn more →Progesterone in pregnancy
If an egg is fertilized, the corpus luteum keeps making progesterone until the placenta takes over. Levels rise each trimester, reaching 58.7 to 214.0 ng/mL in the third trimester at Labcorp. Low progesterone in pregnancy is linked to miscarriage and ectopic pregnancy. A Cochrane review found vaginal progesterone may increase live births for women with early pregnancy bleeding and a previous miscarriage.
Progesterone and estrogen: how they work together
In the first half of the cycle, estrogen makes the uterine lining grow thicker. In the second half, progesterone gets it ready for implantation and keeps its growth in check. If there isn't enough progesterone for the amount of estrogen, the lining can overgrow, called endometrial hyperplasia. Some clinicians call this imbalance estrogen dominance.
Learn more →Why progesterone drops first in perimenopause
Progesterone needs ovulation, and ovulation becomes less reliable in perimenopause. In a study of women sampled through a full cycle, nine anovulatory cycles occurred in the late menopause transition, compared with two in mid-reproductive age, and luteal progesterone fell with each stage. Low progesterone is linked to irregular periods, trouble sleeping, mood changes and hot flashes.
Learn more →Progesterone, sleep and hot flashes
In a trial of eight postmenopausal women, 300 mg of progesterone at bedtime didn't change normal sleep but restored disturbed sleep, with 53% less time awake. In 133 women early in postmenopause, 300 mg nightly reduced hot flash and night sweat scores by 10.0 points vs 4.4 on placebo. In perimenopausal women, a larger trial found no clear difference in scores but better perceived sleep.
Learn more →Natural progesterone vs progestins
Micronized progesterone, sold as Prometrium in the US and Utrogestan in the UK, is identical to the hormone your body makes. Progestins, such as medroxyprogesterone and norethindrone, are synthetic and act like progesterone but have different effects on the breast, heart, brain and bone. Both protect the uterine lining when you take estrogen.
Learn more →Natural progesterone supplements and creams
Over-the-counter progesterone and wild yam creams are widely sold as natural progesterone. In a trial, wild yam cream didn't change progesterone levels or menopause symptoms more than placebo. Progesterone cream trials conflict: one found 83% improvement in hot flashes vs 19% on placebo, while another found no change at 32 mg daily. Creams don't reliably protect the uterus when you take estrogen.
Learn more →Progesterone by the numbers
From the studies on this page
less time awake during disturbed nights with 300 mg progesterone at bedtime, in a small trial
53%
1.8–23.9 ng/mL
0.0–0.1 ng/mL
9
Progesterone ranges depend on cycle day and pregnancy, and differ between labs.
Progesterone treatment options
Micronized progesterone with estrogen HRT
First stepIf you have a uterus and take estrogen, progesterone stops the lining from getting too thick and lowers the risk of uterine cancer. It's taken either for part of each month or every day.
Related guide →Progesterone at bedtime for sleep
Some evidenceProgesterone can make you drowsy, which is why it's usually taken at bedtime. Small trials suggest it improves disturbed sleep in postmenopausal women.
Related guide →Progesterone alone for hot flashes
Limited evidence300 mg nightly reduced hot flashes in early postmenopause, but the trial in perimenopause didn't show a clear benefit. Estrogen-based HRT works better.
Related guide →Wild yam and OTC creams
No good evidenceWild yam cream didn't raise progesterone or ease symptoms in a trial, and OTC creams vary in dose and aren't FDA-approved.
Related guide →
When to see a doctor about progesterone
Irregular, very heavy or very frequent periods in your 40s
See a doctor. Cycles without ovulation are common in perimenopause, but heavy bleeding needs checking and can be treated with progestogens.
More →Taking estrogen without a progestogen when you have a uterus
Ask about adding progesterone. Estrogen alone raises the risk of uterine cancer.
Bleeding or cramping in early pregnancy
See a doctor. A progesterone test may be used to check for miscarriage or ectopic pregnancy.
Urgent: Severe one-sided pelvic pain with a positive pregnancy test
Call 911 or go to the ER. Ectopic pregnancy can be a medical emergency.
Progesterone: questions women ask
What is progesterone?
A sex hormone made mainly by the ovaries after ovulation, and by the placenta in pregnancy. It prepares the uterus for pregnancy and, if you don't get pregnant, its fall triggers your period.
What does progesterone do for women?
It thickens and stabilizes the uterine lining for implantation, regulates menstrual bleeding, supports early pregnancy, prevents contractions and ovulation during pregnancy and prepares the breasts for breastfeeding. It also has calming effects that can help sleep.
What is the difference between progesterone and estrogen?
Estrogen builds the uterine lining in the first half of the cycle and peaks before ovulation; progesterone rises after ovulation to prepare and stabilize it. Estrogen falls later in perimenopause; progesterone often falls earlier because ovulation becomes irregular.
Related →What is natural progesterone?
Micronized progesterone, such as Prometrium, is chemically identical to the progesterone your body makes, and it's prescription-only in pill form. Products sold as natural progesterone over the counter, including wild yam creams, aren't the same and aren't FDA-approved.
What does progesterone do in pregnancy?
It keeps the uterine lining thick and rich in blood vessels to nourish the embryo, prevents contractions that could cause preterm labor, stops further ovulation and helps prepare the breasts. Levels rise through pregnancy and peak in the third trimester.
Where is progesterone produced?
Mainly by the corpus luteum, a temporary gland that forms in the ovary after each ovulation. The adrenal glands make small amounts, and during pregnancy the placenta takes over most production. After menopause, with no ovulation, levels stay very low.
How is progesterone tested?
With a blood test, most often to check whether you've ovulated. Because levels change through the cycle and pregnancy, you may need to note the first day of your last period and repeat the test. It isn't needed to diagnose perimenopause.
Related →Can you take progesterone without estrogen?
Yes, for some uses. Prometrium is approved for missed periods (secondary amenorrhea) on its own, and in a trial 10 days of treatment led to a withdrawal bleed in 80% of women. For menopause, it's usually paired with estrogen to protect the uterus.
Are natural progesterone supplements effective?
Mostly not. Wild yam cream didn't change hormone levels or symptoms in a trial, and a 32 mg progesterone cream had no effect on hot flashes, mood or bones in another. Prescription micronized progesterone is the tested option.
Related →What are the effects of low progesterone?
Outside pregnancy, low progesterone is linked to irregular periods, trouble conceiving, mood changes, trouble sleeping and hot flashes. It's common in perimenopause, PCOS and cycles without ovulation.
Related →Does progesterone make you tired?
It can. Drowsiness and dizziness are known side effects of oral progesterone, so it's usually taken at bedtime. Low progesterone can also leave you tired by disturbing sleep.
Related →Does progesterone cause weight gain?
Not directly, according to Cleveland Clinic: too much or too little progesterone alone isn't usually a cause of weight gain. Some women notice bloating while taking it.
Related →What is the role of progesterone in females?
Its main role is preparing the uterine lining for a fertilized egg and supporting early pregnancy; if you don't conceive, its fall triggers your period. It also regulates menstrual bleeding and balances estrogen's effect on the lining, and it may affect mood and sleep.
Sources
- Cleveland Clinic. Progesterone: natural function, levels and side effects.
- MedlinePlus, US National Library of Medicine. Progesterone test.
- Hale GE, Zhao X, Hughes CL, et al. Endocrine features of menstrual cycles in middle and late reproductive age and the menopausal transition classified according to the Staging of Reproductive Aging Workshop (STRAW) staging system. J Clin Endocrinol Metab. 2007;92(8):3060-7.
- Cleveland Clinic. High estrogen: causes, symptoms, dominance and treatment.
- NHS. Utrogestan (micronised progesterone): about.
- Caufriez A, Leproult R, L'Hermite-Balériaux M, et al. Progesterone prevents sleep disturbances and modulates GH, TSH, and melatonin secretion in postmenopausal women. J Clin Endocrinol Metab. 2011;96(4):E614-23.
- Hitchcock CL, Prior JC. Oral micronized progesterone for vasomotor symptoms--a placebo-controlled randomized trial in healthy postmenopausal women. Menopause. 2012;19(8):886-93.
- Labcorp. Progesterone (test 004317): reference range.
- Devall AJ, Papadopoulou A, Podesek M, et al. Progestogens for preventing miscarriage: a network meta-analysis. Cochrane Database Syst Rev. 2021;4(4):CD013792.
- Santoro N, Brown JR, Adel T, et al. Characterization of reproductive hormonal dynamics in the perimenopause. J Clin Endocrinol Metab. 1996;81(4):1495-501.
- Prior JC, Cameron A, Fung M, et al. Oral micronized progesterone for perimenopausal night sweats and hot flushes a Phase III Canada-wide randomized placebo-controlled 4 month trial. Sci Rep. 2023;13(1):9082.
- Stanczyk FZ, Hapgood JP, Winer S, et al. Progestogens used in postmenopausal hormone therapy: differences in their pharmacological properties, intracellular actions, and clinical effects. Endocr Rev. 2013;34(2):171-208.
- Komesaroff PA, Black CV, Cable V, et al. Effects of wild yam extract on menopausal symptoms, lipids and sex hormones in healthy menopausal women. Climacteric. 2001;4(2):144-50.
- Leonetti HB, Longo S, Anasti JN. Transdermal progesterone cream for vasomotor symptoms and postmenopausal bone loss. Obstet Gynecol. 1999;94(2):225-8.
- Wren BG, Champion SM, Willetts K, et al. Transdermal progesterone and its effect on vasomotor symptoms, blood lipid levels, bone metabolic markers, moods, and quality of life for postmenopausal women. Menopause. 2003;10(1):13-8.
- Prescribing information: Prometrium (progesterone capsules). Acertis Pharmaceuticals, 2026. DailyMed, US National Library of Medicine.
- US Food and Drug Administration. NASEM study on the clinical utility of treating patients with compounded "bioidentical" hormone therapy.
- NICE. Heavy menstrual bleeding: assessment and management (NG88).
- National 911 Program. 911.gov.
- Labcorp. Estradiol (test 004515): reference range and clinical information.
- NICE. Menopause: identification and management (NG23). Updated 2024.
See our editorial policy.
Related guides
Low progesterone symptoms
Irregular or heavy periods, poor sleep, anxiety and hot flashes can signal low progesterone, often the first h…
Progesterone levels
Progesterone ranges in the follicular and luteal phase, in pregnancy and after menopause. Why timing matters a…
Progesterone pills
Micronized progesterone (Prometrium, Utrogestan) vs synthetic progestins like medroxyprogesterone and norethin…
Estrogen vs progesterone
Estrogen builds the uterine lining and drives the first half of the cycle; progesterone stabilizes it after ov…