Menopause Hormone Therapy

Contents

1. How the treatment works
2. Systemic and local forms
3. What the evidence shows on benefit
4. What the evidence shows on risk
5. The label, the timing and the comparison

Candace Cooley counts menopause among the concerns she has treated as a board certified obstetrician and gynecologist, and hormone therapy is easiest to understand by following estrogen step by step from the ovary to the tissues that miss it. At menopause the ovaries make far less estrogen and progesterone, and Medscape’s clinical reference explains that estrogen normally helps the hypothalamus regulate body temperature, so its loss can unsettle that control and produce hot flashes and night sweats; the same fall thins the tissues of the vagina, urethra and bladder and speeds bone loss in the first five years after menopause. In about a quarter of women, the reference adds, the symptoms are debilitating.¹ Hormone therapy puts estrogen back, alone or with a progestogen, to relieve those effects.

How the treatment works

The American College of Obstetricians and Gynecologists describes two types. Estrogen alone is used after a hysterectomy. A woman who still has a uterus also needs a progestin, because estrogen by itself thickens the uterine lining and raises the risk of endometrial cancer. The two can be taken every day together, or with the progestin added for part of each month.² A 2021 review in PubMed Central adds that estrogen taken by mouth passes through the liver first, which raises clotting factors and triglycerides, while estrogen through the skin avoids that first pass and can be given at lower amounts. Taking both hormones every day is the most common pattern in North America; with a monthly progestogen cycle, up to 80 percent of women have a withdrawal bleed, and about 40 percent of those on the daily combination see unscheduled bleeding in the first three to six months. The protective effect of the progestogen is large: in one trial, estrogen alone raised the rate of endometrial hyperplasia to 34 percent, against 1 percent with combined therapy.³

Figure

How estrogen therapy reaches the body

1. 01
   OvaryEstradiol, the main estrogen made by the ovaries, falls at menopause
2. 02
   By mouthOral estrogen passes through the liver first, which raises clotting factors and triglycerides
3. 03
   Through the skinPatches, gels and sprays bypass the liver and can be given at lower amounts
4. 04
   In the vaginaLow amount vaginal estrogen treats local tissue without raising blood levels above the postmenopausal range
5. 05
   UterusA progestogen is added to systemic estrogen to keep the uterine lining from thickening

Systemic and local forms

The college separates systemic from local therapy. Systemic estrogen, in pills, patches, gels and sprays, travels in the blood to the organs that need it; local estrogen, in a vaginal ring, tablet or cream, releases small amounts into the vaginal tissue for women whose main complaint is dryness.² According to the review, low amount vaginal estrogen does not lift blood levels above the usual postmenopausal range, so a progestogen is generally not needed with it.³ NPR’s guide to the therapy notes that many women now use patches rather than pills, since oral therapy slightly raises the risk of clots and stroke, and that micronized progesterone, identical in structure to the body’s own, has replaced the synthetic progestin used in older trials for many prescribers.⁴ The college recommends approved products over custom compounded hormones, whose strength and purity vary.²

What the evidence shows on benefit

Relief of hot flashes is the main use. Medscape cites placebo controlled trials showing up to an 80 percent reduction in hot flashes, sweating and palpitations.¹ The college lists systemic estrogen as the most effective treatment for hot flashes and night sweats, notes that both forms relieve vaginal dryness and that systemic estrogen protects against early bone loss, and adds that combined therapy may lower colon cancer risk.²

Figure

Symptoms and bone at menopause

of women whose menopausal symptoms are debilitating

About 25%

reduction in hot flashes, sweating and palpitations with hormone therapy in trials

Up to 80%

postmenopausal women who develop osteoporosis

1 in 3

Bone is the second major use. Medscape notes that one in three postmenopausal women develops osteoporosis, that hormone therapy works best for prevention when started in the first five years after menopause, and that it is not the first choice once osteoporosis is established. In absolute terms, five years of combined therapy in the Women’s Health Initiative prevented about one hip fracture per 1,000 women under 70 and about eight per 1,000 women aged 70 to 79.¹ The 2021 review concludes that since the 2002 results of the Women’s Health Initiative, it has become clear that risks are low for healthy women younger than 60 or less than a decade past menopause, and that later trials found neutral or favorable effects on heart disease when therapy began in that window.³ The heart side is discussed in cardiovascular risk across the menopause transition, and the symptoms in vasomotor symptoms.

What the evidence shows on risk

The risks are real and depend on type. The college lists a small increase in breast cancer with combined therapy, a small rise in heart attack risk in older women, a small risk of stroke and blood clots that is lower with patches, sprays and rings than with pills, and more gallbladder disease.² STAT reported in 2019 on a pooled analysis of dozens of studies, estimating that 6.3 percent of women who never used hormones developed breast cancer against 8.3 percent of those on five years of continuous combined therapy, about one extra case for every 50 users, with risk persisting for more than a decade after stopping.⁵

Figure

Breast cancer with and without hormone therapy

• Never used hormone therapy6.3
• Five years of continuous combined therapy8.3

Length of use is weighed each year. NPR reports that women commonly stay on therapy for three to five years, though experts quoted there call that a guide rather than a rule, since symptoms last longer in some women.⁴ Systemic therapy is usually not advised after breast or endometrial cancer, stroke, heart attack, blood clots or liver disease.² A cardiologist quoted by CNN adds that high blood pressure, high cholesterol and excess weight call for a careful pause first, and notes that pills may raise clot risk as much as fivefold.⁶

The label, the timing and the comparison

For two decades every estrogen product carried a boxed warning that grew out of the Women’s Health Initiative, whose story is told in the Women’s Health Initiative. The 2021 review attributes the trial’s unexpected heart findings partly to who took part: women with a mean age of 63, typically more than a decade beyond their final period, often carrying cardiovascular risk factors already, and given stronger doses than in later research.³ At a July 2025 panel, Urology Times reports, specialists argued that low amount vaginal estrogen does not travel through the body and should not carry that warning.⁷ A menopause specialist told NPR that for most people the risk of systemic therapy is low, but not zero.⁸ CBS News reported that 76 doctors and researchers asked for a fuller scientific review before any change.⁹ In November 2025 the broad warning was removed, Medscape notes, while a boxed warning about unopposed estrogen in women with a uterus remains.¹

The figure below sets the two main forms side by side. Which, if either, suits one woman is settled with her own clinician.

Figure

Systemic and local estrogen compared

	Systemic estrogen	Local estrogen
Forms	Pills, skin patches, gels and sprays	Vaginal ring, tablet or cream
How it acts	Released into the bloodstream and carried to organs and tissues	Small amounts released directly into vaginal tissue
What it treats	Hot flashes, night sweats and vaginal dryness; protects against early bone loss	Vaginal dryness