Women's Health Initiative

How it works

Benefits

Risks & contraindications

Evidence quality

Highlighted claims

• The WHI studied only oral CEE and oral MPA, so results cannot be extrapolated to other estrogen types, progestogens, or non-oral delivery routes. — Menopause Hormone Therapy: Updated Evidence, Risk Reassessment, and Clinical Guidance
• Most WHI participants were 10 or more years past menopause, making the results poorly applicable to perimenopause or early postmenopause. — Menopause Hormone Therapy: Updated Evidence, Risk Reassessment, and Clinical Guidance
• A 2018 reanalysis found no effect on breast cancer incidence from CEE + MPA after excluding prior estrogen users from the placebo group. — Menopause Hormone Therapy: Updated Evidence, Risk Reassessment, and Clinical Guidance
• After 18 years of follow-up, women who used combination therapy for approximately 5 years or estrogen alone for approximately 7 years did not have increased all-cause, cardiovascular, or cancer mortality. — Menopause Hormone Therapy: Updated Evidence, Risk Reassessment, and Clinical Guidance
• Twenty-year WHI follow-up data found that ovarian cancer incidence and mortality more than doubled among women on estrogen alone, with the difference reaching statistical significance after 12 years. — Menopause Hormone Therapy: Updated Evidence, Risk Reassessment, and Clinical Guidance
• The timing hypothesis holds that initiating hormones earlier after menopause onset provides greater cardiovascular benefit and potentially less harm than late initiation, though it remains an active area of debate. — Menopause Hormone Therapy: Updated Evidence, Risk Reassessment, and Clinical Guidance