Last checked September 2026 against 27 sources · Editorial policy
Progestin vs progesterone
Progestin vs progesterone: progesterone is the hormone your ovaries make; micronized progesterone (Prometrium) is chemically identical to it. Progestins, such as medroxyprogesterone and levonorgestrel, are synthetic. Both are progestogens and both protect the uterine lining during estrogen HRT, but progestins act more strongly and differ in effects on the breast and clotting. In a French cohort, estrogen with progesterone wasn't linked to extra breast cancer risk; estrogen with progestins was.
Progesterone is identical to your own hormone; progestins are synthetic versions used in birth control and some HRT. Differences in side effects and risks.
Progestin vs progesterone: expectation vs reality
What people often expect
“Progestin and progesterone are the same thing with different names”
What the evidence shows
They share one job, protecting the uterus from estrogen, but they aren't the same molecule. The WHI trial that shaped HRT fears used only one progestin, medroxyprogesterone, yet its results were applied to all progestogens. Reviews stress that individual progestins differ in their effects on the heart, brain, breast and bone, so the choice matters.
The difference between progestin and progesterone
Is progestin the same as progesterone?
No. Progestin is an artificial, lab-made form of progesterone. Micronized progesterone is also manufactured, from plant sources, but it's identical to the progesterone your ovaries produce in the second half of the cycle. Medroxyprogesterone works like progesterone but has stronger effects, according to the NHS. The umbrella term for both is progestogen.
Types of progestins and progesterone
Micronized progesterone comes as Prometrium capsules, as vaginal forms used in fertility treatment, and combined with estradiol in Bijuva. Progestins include medroxyprogesterone (Provera tablets, Depo-Provera injection), norethindrone (tablets, CombiPatch, minipills), levonorgestrel (hormonal IUDs, Climara Pro), dydrogesterone, drospirenone and desogestrel. Progestins are used in pills, injections, implants and IUDs.
Learn more →Progestin vs progesterone in HRT: breast cancer
In the French E3N cohort of 80,377 postmenopausal women, estrogen combined with progesterone had a relative risk of breast cancer of 1.00, the same as never using HRT. Estrogen with dydrogesterone was 1.16, and estrogen with other progestins was 1.69. The authors concluded it could be preferable to use progesterone or dydrogesterone.
Learn more →Progestin vs progesterone: blood clots
In a UK study of 80,396 women with blood clots, the combination of conjugated estrogens and medroxyprogesterone carried the highest clot risk (odds ratio 2.10), and estradiol with dydrogesterone the lowest (1.18). Women's Health Concern says micronized progesterone may be associated with less effect on blood clotting, though the evidence, especially for breast cancer, isn't strong.
Side effects of synthetic progesterone
Progestins and progesterone share many side effects: spotting, headaches, breast tenderness, nausea, tiredness, mood changes, rash and acne. The NHS lists weight gain, feeling nervous or depressed, insomnia and feeling hot among common medroxyprogesterone side effects. Micronized progesterone commonly causes drowsiness and dizziness, which is why it is taken at bedtime.
Learn more →Progestins in birth control
Hormonal contraception uses progestins, not progesterone: the minipill, implant, injection and hormonal IUD all contain synthetic progestogens. Progesterone and progestin tablets used for HRT or periods don't prevent pregnancy. That's why, in perimenopause, some women use a 52 mg levonorgestrel IUD to cover both contraception and the progestogen part of HRT.
Learn more →Progestin vs progesterone HRT: which to choose
UK guidance offers micronized progesterone, dydrogesterone, medroxyprogesterone, norethindrone, drospirenone and the levonorgestrel IUD as HRT progestogens. If one causes side effects, another may suit you better. Micronized progesterone and dydrogesterone have the most reassuring breast data; the IUD suits women who also need contraception or have heavy periods.
Progestin vs progesterone for periods
Both can bring on a period or control bleeding. Medroxyprogesterone 5 or 10 mg for 5 to 10 days triggers a bleed 3 to 7 days later; Prometrium 400 mg for 10 days led to a bleed within 7 days in 80% of women in a trial. For heavy periods, NICE suggests the levonorgestrel IUD as a first treatment in many women.
Learn more →Progestin vs progesterone by the numbers
From the studies on this page
is how long a 52 mg levonorgestrel IUD can serve as the progestogen in HRT
5 years
Bar scaled to a 12-year reference span
1.00
2.10
80,377
The breast cancer and clot comparisons come from observational studies, which show links rather than proof of cause.
Which progestogen suits you
Micronized progesterone
First stepBody-identical, cheap as a generic and linked to no extra breast cancer risk in the E3N cohort. Drowsiness is the main downside, so take it at bedtime.
Related guide →Levonorgestrel IUD
First stepProtects the lining for up to 5 years in HRT, provides contraception and treats heavy periods, and avoids daily pills.
Related guide →Medroxyprogesterone or norethindrone
Some evidenceEffective for protecting the lining and controlling bleeding, but linked to higher breast cancer risk with estrogen than progesterone in observational data.
Related guide →OTC progesterone creams
No good evidenceNot FDA-approved, and a 32 mg daily cream raised blood levels only slightly with no effect on symptoms; they don't protect the uterus.
Related guide →
When to talk to a doctor about your progestin or progesterone
Side effects that don't settle after 3 months
Ask about switching to a different progestogen or the hormonal IUD.
Low mood since starting a progestin
Talk to your doctor; mood changes are a known side effect and a different type may help.
You have a uterus and use estrogen without any progestogen
See your doctor. Estrogen alone raises the risk of uterine cancer.
Urgent: Leg swelling, chest pain or sudden breathlessness
Call 911; these can be signs of a blood clot.
Progestin vs progesterone: questions women ask
What is the difference between progestin and progesterone?
Progesterone is the natural hormone, and micronized progesterone is identical to it. Progestins are synthetic compounds that act like progesterone, often more strongly, with different effects on breast tissue, clotting and mood.
Is progestin the same as progesterone?
No. Both are progestogens, but progestin is lab-made and chemically different. Prometrium contains progesterone; Provera contains the progestin medroxyprogesterone.
What is synthetic progesterone?
Another name for a progestin, such as medroxyprogesterone, norethindrone or levonorgestrel. Micronized progesterone is also made in a lab from plants, but it's identical to the body's hormone, so it isn't called synthetic in the same sense.
Which is safer for HRT: progestin or progesterone?
Observational data favor progesterone for breast cancer: 1.00 vs 1.69 relative risk with estrogen in the E3N cohort. The evidence isn't conclusive, and the right choice also depends on bleeding, contraception and side effects.
What forms does progesterone come in?
Capsules (Prometrium), combined estradiol-progesterone capsules (Bijuva) and vaginal forms for fertility treatment. Progestins come as tablets, injections, implants, IUDs and patches.
Do progestins cause more side effects than progesterone?
They share most side effects. Progestins like medroxyprogesterone list weight gain, nervousness and insomnia; progesterone commonly causes drowsiness. Individual responses vary, and switching to another progestogen often helps.
Is the progestin in birth control the same as progesterone in HRT?
No. Birth control uses progestins such as levonorgestrel or desogestrel. HRT can use progesterone or a progestin. Some progestin-only pills don't give enough progestogen for HRT on their own.
Is progesterone from plants natural?
Utrogestan’s progesterone comes from plants and is identical to what your ovaries make, but it’s still a prescription medicine. Plant products sold as natural progesterone aren’t the same: wild yam cream didn’t raise progesterone levels in a trial.
Related →Is norethindrone a progestin or progesterone?
Norethindrone, called norethisterone in the UK, is a synthetic progestin. It is used in some HRT, including the CombiPatch, and UK guidance uses 5 mg tablets as a progestogen option in HRT.
Which progestogen is least likely to raise breast cancer risk?
In the French E3N cohort, estrogen with micronized progesterone had a relative risk of 1.00 and with dydrogesterone 1.16, vs 1.69 with other progestins. These are observational data, not proof of cause.
Sources
- Prescribing information: Prometrium (progesterone capsules). Acertis Pharmaceuticals, 2026. DailyMed, US National Library of Medicine.
- Cleveland Clinic. Progesterone: natural function, levels and side effects.
- 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.
- Fournier A, Berrino F, Clavel-Chapelon F. Unequal risks for breast cancer associated with different hormone replacement therapies: results from the E3N cohort study. Breast Cancer Res Treat. 2008;107(1):103-11.
- NHS. About medroxyprogesterone tablets.
- NHS. Utrogestan (micronised progesterone): common questions.
- Women's Health Concern / British Menopause Society. Fact sheet: HRT types, doses and regimens.
- Prescribing information: Bijuva (estradiol and progesterone capsules). Mayne Pharma, 2026. DailyMed, US National Library of Medicine.
- NHS. Utrogestan (micronised progesterone): about.
- British Menopause Society. Tool for clinicians: HRT preparations and equivalent alternatives. 2024.
- Prescribing information: CombiPatch (estradiol/norethindrone acetate transdermal system). Noven, 2024. DailyMed, US National Library of Medicine.
- Prescribing information: Climara Pro (estradiol and levonorgestrel transdermal system). Bayer HealthCare, 2026. DailyMed, US National Library of Medicine.
- NHS. What is the contraceptive implant?
- Vinogradova Y, Coupland C, Hippisley-Cox J. Use of hormone replacement therapy and risk of venous thromboembolism: nested case-control studies using the QResearch and CPRD databases. BMJ. 2019;364:k4810.
- NHS. Side effects of hormone replacement therapy (HRT).
- NHS. Side effects of medroxyprogesterone tablets.
- Women's Health Concern (British Menopause Society). Contraception for women over the age of 40. Fact sheet, 2025.
- Provera (medroxyprogesterone acetate tablets). US prescribing information, DailyMed.
- NICE. Heavy menstrual bleeding: assessment and management (NG88).
- Mark Cuban Cost Plus Drug Company. Hormone therapy medication prices (checked September 2026).
- 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.
- US Food and Drug Administration. NASEM study on the clinical utility of treating patients with compounded "bioidentical" hormone therapy.
- NHS. Utrogestan (micronised progesterone): side effects.
- NHS. Utrogestan (micronised progesterone): how and when to take.
- National 911 Program. 911.gov.
- 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.
- British Menopause Society. Tool for clinicians: HRT practical prescribing.
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