Key TakeawaysHormone therapy for menopause doesn’t have any effect on future risk of dementiaData from more than 1 million women found no positive or negative effect of hormone therapy on dementia riskWomen considering hormone therapy shouldn’t include dementia risk as a factor, researchers said.MONDAY, Dec. 29, 2025 (HealthDay News) — Hormone replacement therapy for menopause appears to have no influence at all on a woman’s future risk of dementia, a new evidence review concludes.There’s no evidence that hormone therapy either increases or decreases dementia risk among women after menopause, researchers reported Dec. 22 in The Lancet Healthy Longevity.A woman’s decision to use hormone therapy should be guided by other potential benefits and risks, and not by any consideration of dementia, researchers concluded.“Menopause hormone therapy is widely used to manage menopausal symptoms, yet its impact on memory, cognition and dementia risk remains one of the most debated issues in women's health,” said lead researcher Melissa Melville, a doctoral student at University College London in the U.K.“Conflicting research and concerns about potential harms have fueled public and clinical debate, leaving women and clinicians unsure whether menopause hormone therapy might raise or reduce their risk of dementia,” she noted in a news release.The evidence review follows a November announcement by the U.S. Food and Drug Administration (FDA) that it would remove “black box” warnings on hormone therapy products for menopause, researchers said. The warnings had included disproven claims about long-term health risks, including a claim of potential increased risk of dementia.For the study, researchers pooled data from one controlled trial and nine previous research projects involving more than 1 million participants.“Across the globe, dementia disproportionately affects women, even after accounting for women’s longer lifespans, so there’s a pressing need to understand what might be driving that risk, and to identify ways to reduce women’s risk of dementia,” Melville said.Researchers found no significant effects from hormone therapy on dementia risk, even after slicing up the data to consider the timing, duration and type of therapy.Researchers also found no evidence that hormone therapy affected the risk of women who have early menopause.“Currently, the World Health Organization [WHO] provides no guidance on menopause hormone therapy and cognitive outcomes, leaving a critical gap for clinicians and policymakers,” senior researcher Aimee Spector said in a news release. She’s a professor of clinical psychology of aging at University College London.“To cut through the noise, we reviewed the most rigorous research there is on the subject and found that menopause hormone therapy does not appear to impact dementia risk either positively or negatively,” she said.“This review will help to inform the upcoming WHO guidelines on reducing the risk of cognitive decline and dementia, which are expected to be released in 2026,” Spector noted.However, researchers said more clinical trials are needed, particularly among women from minority backgrounds or those with early menopause, premature ovarian insufficiency or mild cognitive impairment.“More high-quality, long-term research is still needed to fully understand the long-term impacts of menopausal hormone therapy,” Spector said.More informationThe Menopause Society has more on hormone therapy.SOURCE: University College London, news release, Dec. 22, 2025 .What This Means For YouWomen shouldn’t worry about dementia risk if they’re considering hormone therapy for menopause..Sign up for our weekly HealthDay newsletter