If you’re a woman navigating menopause, you’ve probably heard mixed messages about hormone replacement therapy (HRT). Medical societies like the North American Menopause Society, the American College of Obstetricians and Gynecologists, and the American Association of Clinical Endocrinologists all support HRT as a treatment for bothersome menopausal symptoms—especially in early menopause. So why does it feel like so few women are offered this potentially life-improving therapy?
Let’s break down the history, the science, and the misconceptions that have shaped women’s health for the past few decades.
The HRT High Point—And the Sudden Drop
Before 2002, HRT was basically the standard of care for women entering menopause. Around 30% of menopausal women were taking it, and the most common HRT drug was the world’s top-selling medication. Research then suggested HRT didn’t just help with hot flashes—it actually reduced overall risk of death (all-cause mortality) and lowered the chance of developing cardiovascular disease.
HRT was also shown to decrease the risk of fractures from osteoporosis by 30-40%. Depending on the specific type, it even reduced the risk of colorectal cancer and new-onset diabetes. Women on HRT had fewer heart attacks and a 30-40% reduction in their overall risk of dying.
Enter the Women’s Health Initiative: A Game-Changer (But Not in a Good Way)
Everything changed with the Women’s Health Initiative (WHI), a massive American study that looked at the effects of synthetic conjugated equine estrogens (estrogens from pregnant horses) and synthetic progestins (not the same as the body’s natural progesterone) on women who had already been in menopause for a long time.
When the WHI results hit the media in 2002 and 2004, the message was clear—at least on the surface: HRT might increase the risk of breast cancer and cardiovascular disease. Doctors and patients panicked. Practically overnight, HRT prescriptions plummeted. In retrospect, this was probably one of the biggest public health missteps in women’s medicine in the last century.
But here’s the kicker: Later analysis showed that women who started HRT when they entered menopause actually had a 30-40% reduction in risk of death and heart attacks, regardless of which drug was used in the WHI trial. The increased risks were only seen in women who started HRT more than 10 years after menopause began—and even then, the main concern was a slight uptick in strokes and blood clots, with no benefit for heart health.
Sorting Through the Confusion
The initial WHI findings were misunderstood by almost everyone—doctors, patients, and even medical societies. As a result, a proven tool for improving quality of life and long-term health was sidelined. Many women were left to struggle with hot flashes, night sweats, weight gain, low libido, and a higher risk of fractures, all because HRT was suddenly “off-limits.”
It took years for the medical community to re-examine the data. Now, the advice is to use HRT within 10 years of menopause—for symptom relief and health protection—but usually for the shortest time possible.
What Do Recent Studies Show?
Let’s look at some of the big studies that have shaped our current understanding:
Finnish Study
- Who: 489,105 Finnish women using HRT from 1994 to 2009 (3.3 million “HRT years”)
- Results:
- Cardiovascular disease risk dropped by 18-54%, depending on how long women took HRT.
- Overall risk of death decreased by 12-38%, again tied to duration of use.
- The longer women used HRT, the greater the protection—no matter when they started.
- Just one year of HRT cut the risk of death from stroke by 18%; 10 years brought a 40% reduction in deaths from heart attacks and strokes.
- Conjugated equine estrogens (used in the original WHI) were rare in Finland, less than 1% of users.
- Both oral and skin (topical) estrogens were used.
Reference: Mikkola TS et al, Menopause. 2015
Danish Study
- Who: 698,098 HRT users, women aged 51+ starting HRT between 1995-2001.
- Results:
- Dermal (skin-based) HRT users had a 38% lower risk of dying from cardiovascular disease.
- Oral HRT users didn’t see this benefit.
- Combining estrogen with synthetic progestins removed the heart protection, but didn’t increase risk above non-users.
Reference: Løkkegaard, E et al, European Heart Journal, 2008
UK Stroke Study
- Who: 15,710 stroke patients and 59,958 controls between 1987 and 2006.
- Results: Increased stroke risk was only seen in women taking high-dose oral HRT. Other forms and doses didn’t show increased risk.
Reference: Renous C et al, BMJ 2010
Blood Clots and HRT: VTE Studies
- UK QResearch and CPRD Study (1998-2017)
- 80,396 women with venous thromboembolism (VTE) vs 391,494 controls.
- Conjugated equine estrogens with synthetic progestins raised blood clot risk.
- Oral estradiol with synthetic progestins had some risk.
- Skin-based (dermal) HRT, regardless of progestin, did not increase blood clot risk.
Reference: Vinogradova, Y et al, BMJ 2019
- French ESTHER Study (1999-2006)
- Dermal estrogen: no increased blood clot risk.
- Oral or synthetic estrogen: increased risk.
- Natural progesterone (“micronized progesterone”): no blood clot risk.
- Synthetic progestins: increased risk.
Reference: Marianne Canonico et al, Circulation, 2007
The Bottom Line
So why aren’t more women offered HRT? Much of it comes down to lingering fear and confusion from older studies—especially the WHI—despite mountains of newer research showing clear benefits (when started early and with the right type of hormone). Modern recommendations support HRT for symptom relief in early menopause, and it may also offer protection from heart disease, fractures, and even death.
If you’re considering HRT, talk with your doctor about your personal risks and the type and route of HRT that might be right for you. The science is on your side!
- Mikkola TS et al. “Estradiol-based postmenopausal hormone therapy and risk of cardiovascular and all-cause mortality.” Menopause, 2015.
- Løkkegaard E et al. “Hormone therapy and risk of myocardial infarction: a national register study.” European Heart Journal, 2008.
- Renoux C et al. “Transdermal and oral hormone replacement therapy and the risk of stroke: a nested case-control study.” BMJ, 2010.
- Vinogradova Y et al. “Use of hormone replacement therapy and risk of venous thromboembolism: nested case-control studies.” BMJ, 2019.
- Canonico M et al. “Hormone Therapy and Venous Thromboembolism Among Postmenopausal Women: The ESTHER Study.” Circulation, 2007.
If your doctor is still spooked by outdated studies, it might be time for a second opinion. Women deserve to feel good in menopause — and the evidence says HRT can help.
