A comprehensive new analysis of over a million women’s health data confirms that menopause hormone therapy (MHT), also known as hormone replacement therapy (HRT), is not demonstrably linked to an increased risk of dementia. The review, commissioned by the World Health Organization (WHO), is the most rigorous investigation to date on this debated topic, and its findings will inform upcoming WHO guidelines expected in 2026.
Why This Matters: Conflicting Evidence and Women’s Health
The connection between MHT and cognitive decline has been a source of uncertainty for both patients and clinicians. Early studies suggesting potential harm led to a sharp decline in prescriptions globally, despite serious limitations and later-emerging caveats. The lack of clear guidance from major health organizations like the WHO has left many women unsure whether this therapy could raise or reduce their dementia risk.
This matters because dementia is a growing global health crisis, and any potential risk factor – or reassurance against one – is critical for informed medical decision-making.
Key Findings: No Strong Evidence Either Way
The systematic review found no strong evidence that MHT increases or decreases the risk of dementia. Most studies were observational, meaning they can only show associations, not prove cause-and-effect. The results were inconsistent, with some studies suggesting slight positive or negative links, but all with low certainty.
Variations in MHT formulations, dosages, and timing of prescription further complicated comparisons. Women who start therapy after age 60 may face higher risks, making early intervention potentially more beneficial. One randomized trial suggested a possible increased risk with estrogen-only products in women over 65, but the authors themselves labeled the certainty of that result “low.”
Current Guidelines and Future Research
The FDA recently announced plans to remove “black box” warnings on MHT products cautioning about increased dementia risk, aligning with the new review’s findings. The European Society of Human Reproduction and Embryology also recommends MHT for dementia prevention in women with premature ovarian insufficiency.
However, researchers stress the need for more high-quality data, particularly on those who experience early menopause due to hysterectomies or oophorectomies (surgical removal of the uterus or ovaries). Studies have linked early oophorectomy to increased brain risks and hysterectomy to a higher stroke risk, but comparative data remains insufficient.
“Overall, available evidence to date does not support MHT solely for risk reduction of dementia nor does MHT increase dementia risk,” the review concludes.
Menopause research remains significantly underfunded, hindering progress in this critical area of women’s health. Building trust in this life-changing therapy will require time, robust research, and clear communication from medical authorities.
