Does HRT Affect Your Brain? What New Science Says
What if everything we’ve been told about hormone therapy and dementia risk… isn’t quite right?
A new study published in The Lancet Healthy Longevity is challenging long-held fears around hormone therapy and brain health. And if you’re in midlife (or heading there), this matters more than you think.
What’s This About?
This study, “Menopausal hormone therapy and risk of mild cognitive impairment and dementia,” looks at whether menopausal hormone therapy (MHT) affects the risk of memory decline or dementia. This is something so many of us are thinking about, right?
Let me first explain a few acronyms:
MHT (Menopausal Hormone Therapy): Estrogen (with or without progesterone) used to treat menopause symptoms.
MCI (Mild Cognitive Impairment): Early stage of memory loss that can precede dementia
Dementia: A decline in cognitive function severe enough to impact daily life
For years, women have been told that hormone therapy might increase dementia risk, especially after age 65. That fear has shaped decisions for decades. This study asks: Is that actually true when we look at all the best available evidence?
The relationship between hormone therapy and brain health is not as clear-cut, or as scary, as once thought.
Here’s a special roundtable conversation from the Hack My Age: Menopause Upgrade podcast where I break down maximizing HRT, brain health and trauma.
When & Who?
Researchers looked at multiple high-quality studies that had thousands of women across different ages and treatment types. They reviewed 15 studies, included randomized controlled trials (the gold standard for studies) and observational studies, and focused on midlife and older women using hormone therapy.
Much of the fear around HRT comes from older studies like WHIMS (Women’s Health Initiative Memory Study), which looked at women starting HRT after age 65, not actually during perimenopause, when symptoms can be at their worst.
Timing, type, and delivery of hormones matter a lot.
What Did They Find?
There is no clear evidence that hormone therapy increases or decreases dementia risk.
What the data actually showed:
- No consistent increase in dementia risk
- No strong protective effect either
- Evidence quality = low to moderate certainty
But here’s the nuance most headlines miss:
- Older studies used oral estrogen + synthetic progesterone (a.k.a. progstin)
- Newer approaches include:
- Transdermal estrogen (patches, gels, creams, sprays)
- Body-identical micronized progesterone
- Starting earlier (closer to menopause)
These modern approaches are understudied, meaning we don’t yet have definitive answers
The scary narrative that “HRT causes dementia” is really not supported by strong evidence, but that being said, we still need better research on modern protocols.
Why Does This Matter?
Because millions of women and their doctors are making decisions based on outdated or incomplete information.
Let’s not forget that women are living longer than ever, brain health is a top concern in midlife, and many women avoid HRT because they are afraid of cancer and dementia.
But this study suggests the risk may have been overstated or misunderstood. Avoiding hormone therapy out of fear alone is not evidence-based.
What Am I Doing About It?
I am trying to break down the science so we can make informed, empowered decisions.
On the Hack My Age: Menopause Upgrade podcast, I often explore:
- Hormones & brain health
- Sleep, inflammation, and cognition
- How lifestyle and biology intersect in midlife
Here’s a relevant episode to go deeper.
I personally opted to start bioidentical estradiol, progesterone and testosterone before I started menopause when I was 50. I feel comfortable with my decision, but that doesn’t mean you have to take HRT too.
This isn’t about “take HRT” or “don’t take HRT”. It’s about informed choice.The science continues to evolve and I am staying on top of it. I may decide to change my mind.
Practical Tips
Hormones are just one piece of the puzzle, your daily habits matter even more.
1. Prioritize sleep. Poor sleep is one of the strongest risk factors for cognitive decline.
2. Strength train and include cardio. Muscle mass is directly linked to brain health and longevity, while training the heart and keeping good blood flow to the brain is also protective.
3. Eat for your brain. Focus on omega-3 fats, polyphenols (berries, olive oil), and stable blood sugar.
4. Reduce chronic stress. Cortisol dysregulation impacts memory and brain structure.
5. Personalize your HRT decision. If you’re considering hormone therapy, look at timing (earlier is usually better), ask about the different formulations, and work with a practitioner who understands modern protocols. Check out this blog article to learn how to prepare for your first menopause visit.
Your lifestyle is your baseline. Hormones are a layer, not the whole story.
This study doesn’t give us all the answers, but it does something just as important: it challenges fear-based narratives. And for women navigating midlife, that shift, from fear to informed choice, is everything.
FAQ: HRT & Brain Health
Does hormone therapy prevent dementia?
No clear evidence shows that hormone therapy prevents dementia.
Is HRT safe for brain health?
Current evidence suggests it is not clearly harmful nor protective, it depends on timing, type, and individual factors.
When is the best time to start HRT?
Starting closer to menopause currently is more beneficial, but it’s never too late to have the discussion with your doctor. Age alone is not a good enough reason to deny a woman HRT.
What type of HRT is safest?
Newer forms like transdermal estrogen and body identical progesterone are thought to be safer, but more data is needed.
Can lifestyle changes reduce dementia risk?
Absolutely. Sleep, exercise, diet, and stress management have strong evidence for protecting brain health.
Zora Benhamou is a gerontologist who studies aging and is dedicated to challenging menopause stigma and ageist stereotypes. As the host of the Hack My Age podcast, she focuses on empowering women navigating the menopausal transition through evidence-based techniques that support your 80 year old self.Reference: Melville, M., He, L., Desai, R., Nyamayaro, P., Fox, C., Kothari, K. U., Condron, P., Miao, M., Hickey, M., & Spector, A. (2025). Menopause hormone therapy and risk of mild cognitive impairment or dementia: a systematic review and meta-analysis. The Lancet Healthy Longevity, 100803.