No Association Between Menopause Hormone Therapy and Dementia Risk
After decades of concern and conflicting information, a World Health Organization-commissioned systematic review and meta-analysis was published in The Lancet Healthy Longevity and found no evidence that menopause hormone therapy increases or decreases dementia risk in postmenopausal women.
The comprehensive review analyzed data from over one million participants across ten studies (1 clinical trial and 9 observational studies), making it the most rigorous examination of this hotly debated topic to date.
What the Research Found
The international research team found no significant association between menopause hormone therapy and the risk of dementia or mild cognitive impairment. This held true regardless of when women started hormone therapy (ages 45-55 or ≥60), how long they used it, and what type of hormones they took (estrogen-only or combined therapy, no studies evaluated the use of testosterone).
Lead researcher Melissa Melville explained that dementia disproportionately affects women worldwide, even accounting for longer lifespans, creating an urgent need to understand what drives this risk. For years, conflicting research left both women and healthcare providers uncertain about whether hormone therapy might help or harm cognitive health.
Why This Matters Now
This study arrives at a pivotal moment. In November 2025, the U.S. Food and Drug Administration removed “black box” warnings from hormone therapy products, which had included claims about increased dementia risk.
The findings reinforce current clinical guidance that menopause hormone therapy should be guided by perceived benefits and risks, not for dementia prevention. Canadian medical organizations, including the Society of Obstetricians and Gynaecologists of Canada (SOGC), already base their hormone therapy recommendations on an individual risk-benefit assessment and centered on managing menopausal symptoms like hot flashes, night sweats, mood changes, and sleep disturbances, rather than dementia prevention. This study validates that approach.
Study Limitations and Future Research Needs
While this study provides valuable reassurance, it’s important to understand what it can and cannot tell us. The researchers acknowledged several limitations and areas for further investigation:
- Most participants in the reviewed studies were White women, limiting the applicability of findings to women from diverse ethnic and racial backgrounds
- There was insufficient data on women who experienced premature ovarian insufficiency or early menopause (menopause before age 40 or 45, respectively), where long term health risks are different and hormone therapy is often recommended at higher doses
- The studies varied in how they defined and measured cognitive outcomes, making direct comparisons challenging
- The studies varied in their formulations, including different types of hormones, doses, timing of treatment onset, and delivery methods (pills, patches, gels, vaginal preparations), each of which could have different impacts on cognitive outcomes and need to be assessed individually
- Long-term follow-up data was limited in some studies, which is particularly important since dementia typically develops over many years.
The Bottom Line
For women considering or currently using hormone therapy, this research provides reassuring clarity that hormone therapy is unlikely to increase the risk of developing dementia. Treatment decisions should focus on managing symptoms and improving quality of life during the menopausal transition.
If you’re experiencing menopausal symptoms, this is an excellent time to have an open conversation with your healthcare provider about all available treatment options, including both hormonal and non-hormonal approaches. The decision should be based on your individual symptoms, medical history, and personal preferences – not on fears about dementia or other risks like breast cancer that have previously been highlighted in the media.
This study was published in The Lancet Healthy Longevity in December 2025. You can read the full study here:
https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(25)00122-9/fulltext
Dr. Sarah Soles, ND, Menopause Certified Practitioner
