Hormone therapy (HRT/MHT) has had a complicated history. Here is what current evidence shows.
The WHI reanalysis — what actually changed:
The 2002 Women's Health Initiative findings caused millions of women to stop HRT. But 18-year cumulative follow-up (Manson et al., JAMA 2017; 2018) showed:
- All-cause, cardiovascular, and cancer mortality: NO statistically significant difference between HT and placebo (HR 0.99, 95% CI 0.94-1.03)
- Estrogen-alone (women with prior hysterectomy): NO increased breast cancer risk — in fact, a trend toward reduced incidence
- Timing confirmed: women initiating HT within 10 years of menopause had more favorable outcomes
- In February 2026, the FDA removed 'black box' warnings from most HT products
Absolute risk perspective (BMJ Harper et al., 2024):
- The absolute risk of breast cancer with estrogen-plus-progestogen HRT is fewer than 1 additional case per 1,000 women per year of use
- For estrogen-alone therapy, no increased risk was found across all follow-up periods
- This places HRT's risk profile in the same range as many OTC medications
Current clinical recommendations (NICE updated April 2026, The Menopause Society, Endocrine Society):
- HRT is first-line for moderate-severe vasomotor symptoms — Cochrane (Grant et al., 2019) confirms ~75% reduction in hot flash frequency vs placebo
- For women under 60 or within 10 years of menopause, benefits outweigh risks — this is the 'window of opportunity' supported by the WHI reanalysis
- For premature ovarian insufficiency (under 40), HRT is strongly recommended; benefits significantly outweigh risks in this population
- Low-dose oral estradiol (0.5 mg/day): a randomized trial (JAMA, n=225 perimenopausal/postmenopausal women) found it reduced VMS frequency by 52.9% vs 28.6% placebo at 8 weeks
- Transdermal estrogen (patch, gel) has lower blood clot risk than oral
- Compounded bioidentical hormones are NOT recommended — lack FDA regulation
Key NICE 2026 updates:
- Do NOT use FSH testing to diagnose menopause in women aged 45+ with typical symptoms — diagnosis is clinical
- HRT should not be routinely offered solely for cardiovascular prevention
- CBT is recommended for low mood, anxiety, and hot flash bother