What Is Menopausal Hormone Therapy? An Evidence-Based Primer

Menopausal hormone therapy—often called HRT, or simply hormone therapy—is prescription treatment that replaces the estrogen (and, for people with a uterus, adds a progestogen) that declines around menopause. Menopause itself is defined as the point 12 months after the final menstrual period; in the United States it occurs on average around age 51. The years of fluctuating hormones beforehand, called perimenopause, are when many people first notice hot flashes, night sweats, irregular cycles, and sleep or mood changes. This article explains what hormone therapy is established to do, what it isn't, and why the decision is always individual.

What the Evidence Supports

According to The Menopause Society's 2022 position statement, hormone therapy remains the most effective treatment for bothersome vasomotor symptoms (hot flashes and night sweats) and for the genitourinary syndrome of menopause, and it has been shown to prevent bone loss and fracture. FDA-approved hormone therapies are indicated for moderate-to-severe vasomotor symptoms and for the prevention of postmenopausal osteoporosis, among other specific uses.

Just as important is what hormone therapy is not: it is not an anti-aging treatment, and it is not approved to prevent heart disease, dementia, or other chronic conditions. Some people do notice broader improvements—better sleep often follows fewer night sweats, for example—but claims that go far beyond symptom relief and bone protection should prompt healthy skepticism.

Estrogen-Only vs. Combined Therapy

Which hormones you take depends mainly on whether you have a uterus:

• Estrogen-only therapy, generally for people who have had a hysterectomy
• Combined therapy (estrogen plus a progestogen) for people who still have a uterus

The progestogen isn't optional in combined therapy: taking estrogen alone with an intact uterus raises the risk of endometrial (uterine) cancer, and the progestogen protects the uterine lining. Combined regimens can be continuous or cyclic, and the route matters too—systemic options (pills, patches, gels) treat whole-body symptoms, while low-dose vaginal estrogen treats local genitourinary symptoms with minimal absorption.

How the WHI Changed—and Refined—Prescribing

In 2002, the Women's Health Initiative trials reported increased risks of cardiovascular events and breast cancer with combined hormone therapy, and prescriptions fell sharply. But the trial population averaged about 63 years old—well past the age when most people start therapy for symptoms. Later age-stratified analyses found that absolute risks were substantially lower for women in their 50s or within 10 years of menopause. Today's guidance reflects that nuance: for healthy, symptomatic people under 60 or within 10 years of menopause onset, benefits generally outweigh risks; started later, the balance is less favorable. Risk also varies by formulation, dose, route, and duration—one more reason the decision belongs in a clinician's office, not a checkout page.

The Bottom Line

Hormone therapy is an effective, well-studied option for bothersome menopause symptoms in appropriate candidates—and a treatment with real risks for the wrong ones. If you're considering it, bring your full medical history (including any history of breast cancer, blood clots, stroke, or liver disease) to a qualified clinician, and revisit the decision periodically rather than treating it as permanent.