Hormone · Label read 2026-08-15
Progesterone, and the number that explains why it is in your regimen
Every page about progesterone tells you it is added to estrogen to protect the uterus. The size of that protection is printed on the label and almost nobody quotes it: 6 percent endometrial hyperplasia on estrogen plus progesterone against 64 percent on the same estrogen alone, over 36 months, in a randomized double-blind trial with a placebo arm at 3 percent. Below: that table, the difference between micronized progesterone and a synthetic progestin, and what each of the 8 platforms we price-verify charges for it.
What is progesterone?
Progesterone is a hormone produced by the ovary after ovulation, and in menopause hormone therapy it is the second drug added to estrogen to keep the lining of the uterus from overgrowing. Estrogen on its own drives that lining to proliferate, and progesterone opposes the effect, which is why a woman with a uterus is prescribed both and a woman without one generally is not. Progesterone and progestin are different words: progesterone is the molecule the body makes, and progestin is the class of synthetic drugs built to act on the same receptor, of which medroxyprogesterone acetate is the one used in the Women's Health Initiative estrogen-plus-progestin trial.
Micronized progesterone sold as Prometrium and as generics is an FDA-approved product with a registration trial behind it. Compounded progesterone preparations, which 3 of the telehealth platforms on our roster dispense, are not FDA-approved and have no such trial, so no comparable rate exists for them. What bioidentical actually means.
Why progesterone is prescribed with estrogen
Systemic estrogen taken on its own by a woman who still has a uterus drives the endometrium to proliferate, and sustained proliferation is how hyperplasia and then endometrial cancer begin. The PEPI trial established the pattern in 1996. The Prometrium label carries a cleaner demonstration, because all three arms ran side by side for three years in the same trial.
| Endometrial finding | Estrogen plus progesteronen=117 | Estrogen alonen=115 | Placebon=116 |
|---|---|---|---|
| Any hyperplasia or worse | 6% (7) | 64% (74) | 3% (3) |
| Adenocarcinoma | 0% (0) | 0% (0) | 1% (1) |
| Atypical hyperplasia | 1% (1) | 12% (14) | 0% (0) |
| Complex hyperplasia | 0% (0) | 23% (27) | 1% (1) |
| Simple hyperplasia | 5% (6) | 29% (33) | 1% (1) |
Percentages and patient counts as printed on the Prometrium label, SPL effective 2026-07-23, read 2026-08-15 from the structured XML. 358 women with an intact uterus were randomized to the three arms; the endometrial-diagnosis table reports 117, 115 and 116. The estrogen arm used conjugated estrogens 0.625 mg daily and the progesterone arm added 200 mg for 12 days of each 28-day cycle.
This is an efficacy table, so it reads in the opposite direction to the side-effect table on our progesterone side effects page. Here the estrogen-alone column is the one showing harm, and the progesterone column is why the drug is worth taking. Do not merge the two tables into a single claim about progesterone.
If you have had a hysterectomy the calculation changes. The FDA-approved vaginal estradiol insert labels we checked state it plainly in the dosage section: “Generally, when estrogen is prescribed for a postmenopausal woman with a uterus, consider addition of a progestogen to reduce the risk of endometrial cancer. Generally, a woman without a uterus does not need to use a progestogen in addition to her estrogen therapy.” The labels note one exception, a history of endometriosis. In the Women's Health Initiative, the estrogen-alone arm was run specifically in women with a hysterectomy for that reason.
Progesterone against progestin, and why the distinction is load-bearing
If you arrived here believing hormone therapy causes breast cancer, the result you are carrying almost certainly came from a regimen that used a synthetic. The Women's Health Initiative estrogen-plus-progestin arm used conjugated equine estrogens with medroxyprogesterone acetate, a progestin. Micronized progesterone was not in it.
Micronized progesterone is the molecule the ovary produces, milled fine enough to absorb when swallowed. Medroxyprogesterone acetate is a different compound engineered to hit the same receptor. They share an indication and they do not share a structure, and the label of the estradiol product you are prescribed will say “progestogen” for either one, which is where most of the confusion starts.
The Menopause Society 2022 position statement is the reference clinicians work from on this question. It is worth reading before you accept either version of the story.
What progesterone costs, provider by provider
Each line is the provider's own published product string, kept verbatim including its verification label, so you can see exactly what was checked and when. 8 of the 13 women's-wing platforms we track dispense progesterone. 2 publish what it costs and 6 do not.
- Micronized progesterone (from $23/mo)
Molecule named: Micronized progesterone · Product type: Both · Progesterone priced separately
- Estrogen body cream with progesterone ($89/mo)
- Progesterone capsules (from $39/mo)
- Progesterone body cream ($89/mo)
Molecule named: Not specified · Product type: Compounded · Progesterone priced separately
- Estrogen-progestin (generic Prempro, Bijuva, Mimvey)
- Progesterone (generic Prometrium, Crinone)
Molecule named: Both, named separately · Product type: Brand · No separate progesterone price published
- Estradiol, progesterone (women's line)
Molecule named: Not specified · Product type: Both · No separate progesterone price published
- Progesterone [Reported]
Molecule named: Not specified · Product type: Brand · No separate progesterone price published
- Estrogen and progesterone hormone replacement in patch, suppository and topical forms [Verified July 2026]
Molecule named: Not specified · Product type: Brand · No separate progesterone price published
- Progesterone
Molecule named: Not specified · Product type: Compounded · No separate progesterone price published
- Micronized progesterone where indicated [Verified July 2026]
Molecule named: Micronized progesterone · Product type: Compounded · No separate progesterone price published
The cheapest published monthly progesterone on this roster is Alloy, from $23/mo, against a platform price of $40/mo. Two numbers, and the second one is the one most sites print. Full price table on our cheapest HRT page, scores and grades on the rankings.
3 of the 8 name which molecule you get in their published formulary. The rest print the word progesterone and leave you to find out at the pharmacy whether it is micronized progesterone or a progestin. 3 dispense a compounded preparation, which is mixed by a pharmacy rather than approved by the FDA and therefore has no registration trial behind it. What that means in practice. Head to head on the compounded question: Winona against Gala Health.
Cyclic and continuous dosing, and the two label facts nobody mentions
There are two ways progesterone is given in a menopause regimen and they produce different bleeding patterns. Cyclic dosing is the one the Prometrium label describes for endometrial protection: 200 mg orally as a single daily dose at bedtime, for 12 days sequentially per 28-day cycle, in a postmenopausal woman with a uterus receiving daily conjugated estrogens tablets.Twelve days on, sixteen days off, repeating, which typically produces a scheduled withdrawal bleed. Continuous dosing gives a smaller dose every day with no break and is intended to avoid a bleed. That second regimen is worth checking before you assume the two are equally documented: the Prometrium label prints only the cyclic schedule for endometrial protection, and the only other regimen it carries is 400 mg for 10 days for secondary amenorrhea. A continuous daily prescription is a prescriber's judgement rather than a dose printed on that label. Neither is the correct answer in the abstract. Which one you are given depends on how recently you went through menopause and how you tolerate bleeding, and that is a conversation with the clinician who writes the prescription.
The peanut oil contraindication
Prometrium capsules contain peanut oil and are contraindicated in patients allergic to peanuts. It sits in the CONTRAINDICATIONS section, inside the same numbered item as hypersensitivity to the ingredients, and it is repeated on the patient leaflet. Generic micronized progesterone capsules commonly use the same vehicle. If you have a peanut allergy, this is the question to ask before the prescription is written rather than after the box arrives.
Why it is dosed at night
Prometrium capsules may cause transient dizziness and drowsiness and should be used with caution when driving a motor vehicle or operating machinery. Prometrium capsules should be taken as a single daily dose at bedtime.The sedation is a labelled effect rather than a rumour, and the bedtime instruction is the label's own. Some women read that effect as a benefit and some read it as grogginess the next morning. Either way, taking the dose with breakfast works against the label.
FAQ
Progesterone, answered
What is progesterone?
Progesterone is the hormone the ovary produces after ovulation, and in a menopause regimen it is the drug added to estrogen to protect the lining of the uterus. Estrogen taken on its own makes that lining grow, and progesterone opposes that growth, which is why it is prescribed to a woman who still has a uterus and generally is not prescribed to a woman who does not. Progesterone and progestin are not the same word: progesterone is the molecule the body makes, and progestin is the class of synthetic drugs designed to act on the same receptor, of which medroxyprogesterone acetate is the one used in the Women's Health Initiative estrogen-plus-progestin arm.
Why is progesterone prescribed with estrogen?
To prevent endometrial hyperplasia, and the label prints the size of the effect. In the randomized double-blind trial reported on the Prometrium label, 358 postmenopausal women with an intact uterus were treated for up to 36 months. Hyperplasia or worse was found in 6 percent of the arm taking conjugated estrogens 0.625 mg plus cyclical progesterone 200 mg, in 64 percent of the arm taking the same conjugated estrogens alone, and in 3 percent of the placebo arm. Atypical hyperplasia, the finding closest to cancer in that table, ran 12 percent on estrogen alone against 1 percent on the combination. That is the reason the second drug is in the regimen.
What is the difference between progesterone and progestin?
Progesterone is the molecule the ovary makes. Micronized progesterone, sold as Prometrium and as generics, is that molecule ground fine enough to absorb when swallowed, so it is structurally identical to what the body produces. A progestin is a synthetic compound built to act on the progesterone receptor and structurally different from progesterone. Medroxyprogesterone acetate, sold as Provera and as the progestin half of Prempro, is the one that matters historically: the Women's Health Initiative estrogen-plus-progestin arm used conjugated equine estrogens with medroxyprogesterone acetate, and that trial is the source of most of what people believe about hormone therapy and breast cancer. The estrogen-alone arm of the same trial, run in women who had a hysterectomy, did not show the same breast cancer signal. Whether micronized progesterone carries a lower risk than a synthetic progestin is a question the observational data has addressed and randomized trials have not: the E3N cohort reported different risks for different progestogens. Observational cohorts cannot settle causation, so the honest reading is that the two are not interchangeable and the evidence separating them is not trial-grade.
What to avoid while taking progesterone?
Two things are on the label and almost never printed on a consumer page. Prometrium capsules contain peanut oil and are contraindicated in patients allergic to peanuts. A woman with a peanut allergy who is handed a Prometrium capsule has a labelled contraindication, and generic micronized progesterone capsules commonly use the same vehicle, so the ingredient list is worth reading. Separately, the label warns that the capsules may cause transient dizziness and drowsiness and should be used with caution when driving or operating machinery, which is why the dose is taken at bedtime rather than in the morning. Alcohol and anything else sedating stacks on top of that effect.
What happens when you start taking progesterone?
The sedation shows up first and it is on the label rather than anecdotal: Prometrium capsules may cause transient dizziness and drowsiness, and the label directs a single daily dose at bedtime for that reason. On the label's three-year adverse-reaction table the reactions reported most often on the combined regimen were headache at 31 percent against 27 percent on placebo, breast tenderness at 27 percent against 6 percent on placebo, joint pain at 20 percent against 29 percent on placebo. 1 of those 3 was no worse than placebo, which is the column almost nobody prints. Bleeding patterns change depending on which regimen you are given: cyclical dosing for 12 days out of every 28 is designed to produce a withdrawal bleed, and continuous daily dosing is designed not to. Ask which one you are on before you decide something has gone wrong.
Do you need progesterone if you have had a hysterectomy?
Generally no, and the labels say so in the dosage section rather than in fine print. The FDA-approved vaginal estradiol insert labels we checked carry the same sentence: "Generally, when estrogen is prescribed for a postmenopausal woman with a uterus, consider addition of a progestogen to reduce the risk of endometrial cancer. Generally, a woman without a uterus does not need to use a progestogen in addition to her estrogen therapy." The same labels note the exception, that a woman without a uterus who has a history of endometriosis may still need one. Progesterone in a menopause regimen is endometrial protection, so with no endometrium there is generally nothing to protect. A provider adding it anyway should be able to say why.
How much does progesterone cost?
Of the 8 women's-wing platforms we track that dispense progesterone, 2 publish what the progesterone itself costs and 6 fold it into a platform price without breaking it out. The cheapest published monthly figure is Alloy, from $23/mo. That gap is the reason this site grades price transparency separately from quality of care: a platform can be excellent and still refuse to tell you what the second drug in your regimen costs until after you have paid for the consult.
Related
- Estradiol, explained and then priced the other half of the regimen
- Vaginal estrogen, and why it is priced like a different drug the route that generally needs no progesterone
- Progesterone side effects with the placebo column
- What bioidentical actually means
- Cheapest verified HRT and the full rankings
Sources
- Prometrium (progesterone, USP) capsules prescribing information, DailyMed (SPL effective 2026-07-23, read 2026-08-15 from the structured XML). Source for the endometrial-hyperplasia table, the dosing regimens, the peanut oil contraindication and the drowsiness warning.
- Prometrium approval record, FDA Drugs@FDA
- Effects of hormone replacement therapy on endometrial histology in postmenopausal women, PEPI Trial, JAMA 1996 (PMID 8569016)
- Risks and benefits of estrogen plus progestin in healthy postmenopausal women, Women's Health Initiative, JAMA 2002 (PMID 12117397)
- Effects of conjugated equine estrogen in postmenopausal women with hysterectomy, Women's Health Initiative, JAMA 2004 (PMID 15082697)
- Unequal risks for breast cancer associated with different hormone replacement therapies, E3N cohort study, Breast Cancer Res Treat 2008 (PMID 17333341)
- The 2022 hormone therapy position statement of The North American Menopause Society (PMID 35797481)
This is general information, not medical advice. Progesterone is a prescription medicine and whether you need it, in which form, on which schedule, is a decision for you and a licensed clinician. Reviewed by Iacob Pastina.
Midi Health
Sesame Care