Is hormone therapy safe after menopause?

For healthy women under 60 or within 10 years of menopause, hormone therapy is reasonably safe for hot flashes. It raises the risk of blood clots, stroke and, with a progestin, breast cancer. Risks rise with age.

Who it's for

Healthy women under 60 or near menopause with bothersome symptoms; not for preventing disease.

What to expect

Fewer hot flashes and fractures, with small added risks of clots, stroke and breast cancer.

Watch out for

Blood clots, stroke, and breast cancer with estrogen plus progestin.

What guidelines say

The North American Menopause Society says the balance is favorable for women under 60 or within 10 years of menopause who have bothersome hot flashes or bone loss, and less favorable when started later1Guideline · 2022The 2022 hormone therapy position statement of The North American Menopause SocietyFor women younger than 60, or within 10 years of menopause onset, without contraindications, the benefit-risk ratio is favorable for treating bothersome hot flashes and preventing bone loss. Started more than 10 years after menopause or after age 60, the balance appears less favorable because of greater absolute ris…The North American Menopause Society. The US Preventive Services Task Force recommends against combined estrogen and progestin to prevent chronic disease in women without symptoms. It does not apply to symptom treatment2Guideline · 2022Hormone Therapy in Postmenopausal Persons: Primary Prevention of Chronic ConditionsThe USPSTF recommends against the use of combined estrogen and progestin for the primary prevention of chronic conditions in postmenopausal persons. (Grade D)US Preventive Services Task Force.

What the studies show

• A review that pooled 33 trials (44,639 women, average age 60) found hormone therapy did not change death from any cause or heart disease overall. It raised stroke risk by about a quarter and clot risk (venous thromboembolism) by about 1.9 times3Meta-analysis · 2024 · 44,639 peopleThe benefits and risks of menopause hormone therapy for the cardiovascular system in postmenopausal women: a systematic review and meta-analysis.MHT improves flow-mediated arterial dilation (FMD) but fails to lower the risk of all-cause death and cardiovascular events, and increases the risk of stroke and venous thrombosis in postmenopausal women. Early acceptance of MHT not only reduces the risk of all-cause death and cardiovascular events but also further…BMC Womens Health. Women who started within 10 years of menopause had fewer deaths and heart events than later starters3Meta-analysis · 2024 · 44,639 peopleThe benefits and risks of menopause hormone therapy for the cardiovascular system in postmenopausal women: a systematic review and meta-analysis.MHT improves flow-mediated arterial dilation (FMD) but fails to lower the risk of all-cause death and cardiovascular events, and increases the risk of stroke and venous thrombosis in postmenopausal women. Early acceptance of MHT not only reduces the risk of all-cause death and cardiovascular events but also further…BMC Womens Health.
• A review of reviews found hormone therapy cut hot flash frequency by more than half and lowered fractures by about 28%. It also raised stroke risk and probably clot risk. Quality of the underlying reviews was moderate to poor4Systematic review · 2021 · 43,188 peopleMenopausal hormone therapy and women's health: An umbrella review.MHT has a complex balance of benefits and harms on multiple health outcomes. Some effects differ qualitatively between ET and EPT. The quality of available evidence is only moderate to poor.PLoS Med.
• In the Women's Health Initiative trial of estrogen plus progestin (16,608 women, 5.2 years), each 10,000 women per year had 7 more heart attacks, 8 more strokes, 8 more lung clots and 8 more breast cancers. They also had 5 fewer hip fractures and 6 fewer colorectal cancers7Randomized trial · 2002 · 8,506 peopleRisks and benefits of estrogen plus progestin in healthy postmenopausal women: principal results From the Women's Health Initiative randomized controlled trial.Overall health risks exceeded benefits from use of combined estrogen plus progestin for an average 5.2-year follow-up among healthy postmenopausal US women. All-cause mortality was not affected during the trial. The risk-benefit profile found in this trial is not consistent with the requirements for a viable…JAMA,11Randomized trial · 2003 · 16,608 peopleEstrogen plus progestin and the risk of coronary heart disease.Estrogen plus progestin does not confer cardiac protection and may increase the risk of CHD among generally healthy postmenopausal women, especially during the first year after the initiation of hormone use. This treatment should not be prescribed for the prevention of cardiovascular disease.N Engl J Med. These figures compare groups, so one woman's gain or harm depends on her starting risk.
• Estrogen alone (in women without a uterus) did not raise heart disease risk in the same trials, and breast cancer was lower than with a dummy pill (placeboplacebo A dummy treatment that looks like the real one, so people can't tell which they got.)9Randomized trial · 2013 · 27,347 peopleMenopausal hormone therapy and health outcomes during the intervention and extended poststopping phases of the Women's Health Initiative randomized trials.Menopausal hormone therapy has a complex pattern of risks and benefits. Findings from the intervention and extended postintervention follow-up of the 2 WHI hormone therapy trials do not support use of this therapy for chronic disease prevention, although it is appropriate for symptom management in some women.JAMA. Estrogen plus progestin raised the risk of dementia in women 65 and older, about 23 extra cases per 10,000 women a year10Randomized trial · 2003 · 2,303 peopleEstrogen plus progestin and the incidence of dementia and mild cognitive impairment in postmenopausal women: the Women's Health Initiative Memory Study: a randomized controlled trial.Estrogen plus progestin therapy increased the risk for probable dementia in postmenopausal women aged 65 years or older. In addition, estrogen plus progestin therapy did not prevent mild cognitive impairment in these women. These findings, coupled with previously reported WHI data, support the conclusion that the…JAMA.
• Large studies following women linked every type except vaginal estrogen to more breast cancer. For 5 years of use from age 50, that is about 1 extra case per 50 users of estrogen plus daily progestin and 1 per 200 for estrogen alone6Meta-analysis · 2019 · 647 peopleType and timing of menopausal hormone therapy and breast cancer risk: individual participant meta-analysis of the worldwide epidemiological evidence.If these associations are largely causal, then for women of average weight in developed countries, 5 years of MHT, starting at age 50 years, would increase breast cancer incidence at ages 50-69 years by about one in every 50 users of oestrogen plus daily progestagen preparations; one in every 70 users of oestrogen…Lancet. These are observationalobservational Studies that watch what happens to people rather than assigning a treatment. They can show links, not cause and effect., so cause is not proven.
• The Women's Health Initiative enrolled women averaging 63, so its results may not apply to women starting near menopause8Guideline · 2010Postmenopausal hormone therapy: an Endocrine Society scientific statement.The major conclusions related to the overall benefits and risks of MHT expressed as the number of women per 1000 taking MHT for 5 yr who would experience benefit or harm. Primary areas of benefit included relief of hot flashes and symptoms of urogenital atrophy and prevention of fractures and diabetes. Risks included…J Clin Endocrinol Metab.

Key studies

Safety

Estrogen alone raises endometrial cancer risk in women with a uterus, and the FDA label carries a boxed warning for endometrial cancer, heart disease, breast cancer and probable dementia13Guideline · 2026Estradiol: FDA drug label (prescribing information)Warnings: Subgroup analyses of women 50 to 59 years of age suggest a statistically non-significant reduction in CHD events (CE [0.625 mg]-alone compared to placebo) in women with less than 10 years since menopause (8 versus 16 per 10,000 women-years) 3 .US Food and Drug Administration. In breast cancer survivors, trials found a higher chance of recurrence, about 1.5 times that of women not taking it5Meta-analysis · 2022 · 4,050 peopleSafety of systemic hormone replacement therapy in breast cancer survivors: a systematic review and meta-analysis.Use of HRT was associated with a detrimental prognostic effect in BC survivors, particularly in those with hormone receptor-positive disease. Alternative interventions to mitigate menopause-related symptoms should be proposed.Breast Cancer Res Treat. Gallbladder disease also rose4Systematic review · 2021 · 43,188 peopleMenopausal hormone therapy and women's health: An umbrella review.MHT has a complex balance of benefits and harms on multiple health outcomes. Some effects differ qualitatively between ET and EPT. The quality of available evidence is only moderate to poor.PLoS Med,9Randomized trial · 2013 · 27,347 peopleMenopausal hormone therapy and health outcomes during the intervention and extended poststopping phases of the Women's Health Initiative randomized trials.Menopausal hormone therapy has a complex pattern of risks and benefits. Findings from the intervention and extended postintervention follow-up of the 2 WHI hormone therapy trials do not support use of this therapy for chronic disease prevention, although it is appropriate for symptom management in some women.JAMA. A clinician decides whether it suits a given person.

What we don't know

• Trials in women starting at 50 to 55 are few, so long-term risks for typical starters are less certain8Guideline · 2010Postmenopausal hormone therapy: an Endocrine Society scientific statement.The major conclusions related to the overall benefits and risks of MHT expressed as the number of women per 1000 taking MHT for 5 yr who would experience benefit or harm. Primary areas of benefit included relief of hot flashes and symptoms of urogenital atrophy and prevention of fractures and diabetes. Risks included…J Clin Endocrinol Metab.
• Which doses, patches or hormone types are safest hasn't been settled in large trials.