What is menopause hormone therapy (HRT)?

What it is

Menopause hormone therapy, also called hormone replacement therapy (HRT), is prescription estrogen for symptoms caused by falling estrogen at menopause. In a woman with a uterus, estrogen alone raises the risk of cancer of the uterine lining (endometrial cancer). The FDA says adding a progestogen, a hormone that acts like progesterone, lowers that risk.^10,4

Women with a uterus who take whole-body (systemic) estrogen therefore usually take a progestogen too. Low-dose vaginal estrogen generally needs none, The Menopause Society says.¹¹

Hormone therapy is used for hot flashes and night sweats (vasomotor symptoms), and for vaginal dryness, pain with sex and some urinary symptoms (the genitourinary syndrome of menopause).^10,2,11

How it works

Estrogens act by binding to estrogen receptors inside cells. Estradiol, the main estrogen the ovaries make before menopause, acts on them far more strongly than estriol, a weaker estrogen formed when the body breaks estradiol down.⁴

Estrogen makes the uterine lining grow. Without a progestogen, that growth can become endometrial hyperplasia, an overgrowth that may come before cancer. A 2020 National Academies of Sciences, Engineering, and Medicine report found that low progesterone doses in some compounded products have not been shown to protect the lining. It also questioned whether progesterone creams can, since they reach very low levels in the blood.^4,11,23

How it is taken

FDA-approved whole-body estrogen comes as pills, skin patches, gels, a spray, one vaginal ring or injections into muscle. Low-dose vaginal estrogen, used for genitourinary symptoms, comes as a cream, tablet, softgel insert or ring, and little of it reaches the blood.^11,33

Progestogens are taken as pills, or with estrogen in a combination patch. Approved progesterone for menopause is a micronized (finely ground) capsule taken by mouth; one approved capsule also contains estradiol.^11,6,5

Compounding pharmacies also make hormones to a prescriber’s order, as creams, troches (lozenges dissolved in the mouth) or pellets placed under the skin. In the US, estriol creams and estradiol or progesterone pellets exist only as compounded products, which are not FDA-approved.^11,23

What the research in people shows

A 2004 Cochrane review of 24 placebo-controlled trials, with 3,329 women followed for 3 months to 3 years, found estrogen pills made hot flashes less frequent and less severe. Hot flashes also eased on placebo.²⁷

The two Women’s Health Initiative (WHI) trials enrolled women aged 50 to 79, average age 63, to test disease prevention, not symptom relief. Both used conjugated estrogens, a mix of estrogens from pregnant mares’ urine. One gave 16,608 women with a uterus combined therapy (the estrogens plus the synthetic progestin medroxyprogesterone acetate) or a placebo. It stopped in 2002, after an average of 5.2 years, when invasive breast cancers crossed a preset safety limit. The hormone group had more strokes, blood clots and breast cancers, and fewer hip fractures and colorectal cancers. A rise in heart disease events could have been chance.^13,11,16,2

The other gave 10,739 women whose uterus had been removed (a hysterectomy) the estrogens alone or a placebo. It stopped in 2004, after an average of 6.8 years, because stroke risk rose with no sign of heart protection. Hip fractures were fewer.^14,2

After 18 years of WHI follow-up, deaths from any cause, cardiovascular disease or cancer did not differ from placebo. After more than 20 years, estrogen alone was linked to fewer breast cancers and breast cancer deaths, and combined therapy to more breast cancers but not clearly more deaths from them.^17,18

Observational studies, which follow women who chose whether to take hormones, point the other way on estrogen alone. A 2019 pooled analysis of such studies, covering 108,647 women who developed breast cancer, linked all hormone therapy except vaginal estrogen to higher risk, rising with years of use. The authors’ estimate applies to women of average weight in developed countries and assumes cause and effect. Five years of use from age 50 would add about one breast cancer by age 69 per 50 users of estrogen plus a daily progestogen. For estrogen alone, it would be about one per 200 users.²¹

A 2015 Cochrane review of 19 randomized trials with 40,410 women found little if any heart benefit, and more strokes and blood clots. Women who started within 10 years of menopause had fewer deaths and heart disease events than with placebo, in moderate-quality evidence, but still more clots.²⁸

Two later trials measured neck-artery thickening, a stand-in (surrogate measure) for heart disease. In KEEPS (727 recently menopausal women, four years), it did not differ between hormones and placebo. In ELITE (643 women, about five years), estradiol slowed it only in women within six years of menopause, and heart scans showed no difference.^19,20

In the 3-year PEPI trial of 596 women, endometrial hyperplasia was far more common with conjugated estrogens alone than with placebo. Women who also took a progestogen, including micronized progesterone, had rates similar to placebo. REPLENISH, a one-year trial reported in 2018, randomly assigned 1,845 women with a uterus to four strengths of the estradiol and progesterone capsule, or, for some with frequent hot flashes, a placebo. The trial’s authors reported no endometrial hyperplasia, but the capsule’s FDA label counts one case with each of its two approved strengths. Most strengths eased hot flashes more than placebo.^22,37,5

The Menopause Society’s current position statement, from 2022, calls hormone therapy the most effective treatment for hot flashes and genitourinary symptoms. It judges benefits to outweigh risks for women under 60 or within 10 years of menopause who have bothersome hot flashes and no reason to avoid hormones. For later starters it judges the balance less favorable, citing greater absolute risks of heart disease, stroke, clots and dementia.^11,12

Side effects and risks

For women with a uterus who take estrogen without a progestogen, the labels put endometrial cancer risk at 2 to 12 times that of non-users. The risk rises with dose and years of use and lasts years after stopping. Labels also cite a pooled analysis of 17 studies linking current use to ovarian cancer.^4,5

In the 50 to 59 group, only the rise in leg-vein clots on combined therapy was unlikely to be chance. Across all ages, the rises in heart disease on combined therapy and lung clots on estrogen alone could also have been chance.^5,4

Labels also report a two- to fourfold higher risk of gallbladder disease needing surgery. Other label warnings include raised blood pressure, liver problems, fluid retention, clots in the retina and severe allergic reactions. Estrogen can also inflame the pancreas in women with high blood fats, and worsen asthma, diabetes, epilepsy, migraine, lupus and some rare disorders. Women taking thyroid hormone may need more of it. A few cases of cancer in endometriosis left after a hysterectomy have been reported.⁴

More common side effects include headache, breast tenderness, irregular bleeding, nausea, bloating, weight gain and, with progestogens, mood swings. The approved progesterone capsule can cause dizziness and drowsiness. It contains peanut oil, so people allergic to peanuts should not take it.^4,11,6

Labels advise stopping whole-body hormones, if feasible, at least 4 to 6 weeks before surgery that raises clot risk, and during long immobility. Some medicines, supplements and foods, such as St. John’s wort and grapefruit juice, can change estrogen levels.^4,5

In the WHI Memory Study of 4,532 women aged 65 or older, probable dementia was diagnosed in 45 per 10,000 women a year on combined therapy and 22 on placebo. The FDA asked for the dementia warning’s removal in 2025 because those women were much older than typical new users. Updated estrogen labels still describe the Memory Study and list dementia in their patient leaflets as a possible serious side effect.^15,2,4,5

Two later trials, KEEPS-Cog (693 recently menopausal women, up to four years) and ELITE-Cog (567 women, almost five years), found no effect on memory or thinking. A 2023 study of Danish health records compared 5,589 women with dementia and 55,890 without. It linked combined therapy to more dementia, even in women who took it only at age 55 or younger, though its authors could not say whether the hormones caused it.^29,30,31

Labels say not to use systemic estrogen with unexplained genital bleeding, current or past breast cancer, an estrogen-dependent cancer, or liver disease. The same applies to a current or past blood clot, stroke or heart attack, and to known clotting disorders. The updated label for one low-dose vaginal ring lists nearly the same conditions but says it is not known how far whole-body risks apply.^4,7

The Menopause Society cites long-term observational studies that found no rise in heart disease or cancer among vaginal estrogen users. The National Academies said hormone pellets are hard to compound reliably, and cited reports of side effects from too much hormone released unpredictably by compounded pellets.^11,23

Options without hormones

The FDA has approved three medicines without hormones for moderate to severe menopausal hot flashes. Fezolinetant was approved in 2023 and elinzanetant in October 2025. Since December 2024, fezolinetant has carried a boxed warning, the most prominent kind, for liver injury. Elinzanetant has none; its label warns of sleepiness, liver enzyme rises, pregnancy loss and seizures.^10,38,39,40

The third is a low-dose capsule of the antidepressant paroxetine. Its boxed warning covers suicidal thoughts and behaviors, a risk its drug class raised in children and young adults. Its label says it may weaken the breast cancer drug tamoxifen.⁴¹

Ospemifene is a non-hormonal pill that acts like estrogen in some tissues. It is approved for moderate to severe painful sex and vaginal dryness due to menopause. Its boxed warning covers endometrial cancer, stroke and deep-vein blood clots. As with estrogen, its label says not to use it with current or past breast cancer, blood clots, stroke or heart attack.⁴²

Flibanserin, a pill without hormones, is FDA-approved for one form of low sexual desire in women under 65. Its label has included women after menopause since December 2025. Its boxed warning covers fainting and severe low blood pressure with alcohol, some other medicines or liver problems.⁴⁴

FDA status

Estrogen products are FDA-approved for moderate to severe hot flashes and vaginal symptoms of menopause. Some are also approved for low estrogen from underactive, failed or removed ovaries, and to prevent osteoporosis; for bone alone, labels say to consider other medicines first.^4,8,33

The progesterone capsule is approved for absent periods (secondary amenorrhea) and, in women with a uterus taking conjugated estrogens tablets, to prevent endometrial hyperplasia. The estradiol and progesterone capsule is approved for moderate to severe hot flashes in women with a uterus.^6,5

On November 10, 2025, the FDA asked makers of menopause hormone products to drop heart and blood vessel disease, breast cancer and probable dementia from boxed warnings. Only systemic estrogen-alone products would keep a box, for endometrial cancer. Updated systemic labels say to consider starting before 60 or within 10 years of menopause, and keep heart and breast cancer risks among the warnings.^2,4,5

On February 12, 2026, the FDA approved the first six new labels, and by October 30, 2026, its list had nine. Some products not on that list have new labels too, such as an estradiol gel. Labels not yet changed keep the older box; one estradiol tablet label, revised in February 2026, still has it.^3,1,9,8

Testosterone for women

No testosterone product is FDA-approved for menopause symptoms or low sexual desire in women. A 2019 global consensus statement endorsed by The Menopause Society supports it only for low sexual desire causing distress after menopause. It says long-term safety is not established.^34,35

Where no product is approved for women, the statement calls a product approved for men reasonable if blood levels stay in the normal range for women. It says compounded testosterone cannot be recommended, for lack of evidence that it works or is safe, unless no approved equivalent is available. It recommends against any form that raises levels above that range, including pellets and injections.³⁵

Bioidentical and compounded hormones

“Bioidentical” describes a hormone with the same chemical structure as one the body makes. The word is often used to market compounded products, but The Menopause Society calls it misleading, since FDA-approved estradiol and progesterone are bioidentical too. Compounded products may mix several hormones and use untested combinations, formulations or routes, such as pellets.^11,6,26

The FDA says it lacks evidence of the safety and effectiveness of compounded bioidentical hormones, or that they are safer or more effective than approved ones. The American College of Obstetricians and Gynecologists advises against routine use of compounded bioidentical hormones when FDA-approved versions exist.^10,26

The 2020 National Academies report found few well-designed trials of compounded hormones and little data on how the body absorbs them. It judged the evidence insufficient to support their overall use. It said prescribers should limit them to a documented allergy to an ingredient in approved products, or a documented need for another dosage form, not patient preference alone.²³

Compounded hormones are sometimes dosed from saliva, urine or blood tests. The Menopause Society calls saliva and urine tests unreliable for dosing and says blood tests are rarely needed.¹¹

No FDA-approved drug for people contains estriol. The FDA says marketed estriol drugs are compounded, and that it lacks evidence that estriol is a “safer form of estrogen,” or of the safety and effectiveness of estriol products. Pharmacies may compound estriol because it has a USP monograph, a published quality standard, which is not FDA approval.^10,23

Some hormone creams are sold without a prescription, the FDA notes. Under a 1993 FDA rule, a nonprescription cream labeled or promoted as containing a sex hormone, such as estrogens or progesterone, is a new drug that needs FDA approval.^10,36

In a 12-week trial of 436 women, estriol vaginal inserts improved measures of vaginal atrophy more than placebo. In a 24-week trial of 251 women, they eased urinary symptoms about as well as an estradiol vaginal ring. In 2020 the National Academies found no studies showing whether compounded estriol works for vaginal atrophy. A 1999 Swedish case-control study compared 789 women with endometrial cancer or a precancerous overgrowth (atypical hyperplasia) with 3,368 women without either. Five or more years of estriol by mouth was linked to higher risk of both; vaginal use showed only weak links.^24,43,23,25

What isn’t known

Questions to ask a clinician