Menopausal hormone therapy (HRT): who, when and why

Evidence summary for clinicians. For discussion, not a prescription. Grades are a GRADE-style reading of the cited sources unless a guideline grade is quoted.

Who it is for

• Bothersome vasomotor symptoms in women under 60 or within 10 years of menopause. The Menopause Society (NAMS 2022) calls the balance favourable for symptoms and for preventing bone loss¹.
• Premature ovarian insufficiency or early menopause, until at least the average age of natural menopause².
• Women at intermediate or high fracture risk within 10 years of menopause, as one first-line option (IMS India)².
• Not for preventing heart disease or other chronic disease alone (USPSTF grade D)⁴.

Evidence grade: Moderate.

Benefits: what the trials show

• Bone. WHI combined therapy cut hip fractures (HR 0.66) and all fractures (HR 0.76)^{5, 6}; oestrogen alone cut hip fractures (HR 0.61)⁷. Cochrane 2025 found clinical fractures RR 0.78, moderate certainty⁸.
• Symptoms. MHT remains the most effective treatment for vasomotor and genitourinary symptoms¹.
• Deaths. No change in all-cause, heart or cancer deaths over 18 years of WHI follow-up⁹.

Harms in absolute terms

Route matters. Oral oestrogen raises clot risk; transdermal oestrogen at standard doses does not, according to the UK guideline¹³. Breast cancer risk rises with duration and is higher with combined than oestrogen-only therapy; little excess follows less than 1 year of use¹⁰.

Evidence grade: Moderate.

When to start and how long

Benefit-risk is better in women under 60 or within 10 years of menopause, and worse after 60 or beyond 10 years because of heart disease, stroke, clots and dementia¹. WHI women aged 50 to 59 had more favourable results than older women^{9, 11}. Re-evaluate benefits and risks at intervals, and keep longer use for a documented reason such as persistent symptoms¹.

Evidence grade: Moderate. Age-group findings are subgroup analyses.

What the guidelines say

Why gynaecology and orthopaedic literature sound different

Menopause societies (NAMS, IMS India) list bone protection as a benefit of MHT and, in IMS India, as a first-line bone option near menopause^{1, 2}. Bone guidelines (NOGG, Endocrine Society, BHOF) are built around fracture risk tools and drugs with fracture trials, with HRT as one option among several^{13, 15, 16}. USPSTF, a prevention body, recommends against MHT for prevention alone⁴.

Interpretation (not a sourced finding). The gap reflects the patients each specialty sees. Gynaecologists see younger symptomatic women for whom bone is a bonus. Orthopaedic surgeons see older women after a fracture, where MHT is rarely started and bisphosphonates or denosumab dominate. Both views are consistent with the same trial data.

Practical summary

• Symptomatic woman under 60 or within 10 years of menopause: MHT is reasonable and protects bone¹.
• Early menopause or POI: replace hormones to the average menopause age².
• Bone alone, no symptoms: guidelines split; discuss, and consider a bisphosphonate^{2, 4}.
• Prefer transdermal oestrogen when clot risk is raised¹³.
• Explain absolute breast cancer numbers by type and duration¹⁰.

Where the evidence is weak

• WHI used one oral regimen (conjugated equine oestrogen with or without medroxyprogesterone) in women with mean age 63. Modern transdermal oestradiol and micronised progesterone have no comparable fracture or breast cancer RCTs^{5, 9}.
• Only one study in the 2025 Cochrane review focused on perimenopausal women⁸.
• Breast cancer figures for type and duration are observational¹⁰.
• The ESE 2025 row is based on the published summary only; the full guideline was not reviewed for this article³.

Related evidence pages

• Bone health in perimenopause: what the evidence shows
• Fracture risk around menopause and how to reduce it
• Osteoporosis around menopause: questions and evidence answers