Brain Fog in Perimenopause

Brain Fog in Perimenopause: What’s Normal, What’s Not

Written by: Dr. Madeleine Clark, ND MSCP

If you’ve ever walked into a room and forgotten why, struggled to find the right word, or felt like your brain just isn’t as sharp as it used to be, you may have wondered: Is this normal or is something happening to me?

For many women in their 30s, 40s, and 50s, these changes in memory and focus are often described as “brain fog.” And while brain fog can feel unsettling, it is a common and usually temporary part of the perimenopause transition, not a sign of dementia.

What Do We Mean by “Brain Fog”?

Brain fog isn’t a medical diagnosis, but a cluster of cognitive changes women frequently report during perimenopause and menopause. These may include:

  • Forgetting names or words mid-sentence

  • Trouble multitasking

  • Feeling slower to recall information

  • Difficulty concentrating or staying focused

Research shows that brain fog in perimenopause often affects reaction time, visual memory, attention, and working memory.

Learn more about depression in perimenopause.

Why Does Brain Fog Happen in Perimenopause?

Several overlapping factors contribute to these changes:

Hormonal Shifts

Estrogen interacts with areas of the brain like the hippocampus and prefrontal cortex, which are critical for memory and attention. As estrogen levels fluctuate, these brain areas may not function as efficiently.

Sleep Disturbances

Hot flashes, night sweats, and insomnia are common in perimenopause, and poor sleep can significantly affect memory and focus.

Download my free Perimenopause Starter Guide for lifestyle tips to support sleep and hormones.

Stress and Mood

Anxiety, depression, or high stress levels also impact cognitive performance. These are more likely to flare during hormonally sensitive windows and during a stage of life where we are often under many demands!

Brain Fog vs. Dementia

It is very common for women to worry that brain fog means early dementia. The reassuring truth is that they are not the same.

  • Dementia is uncommon in midlife and is a progressive neurological disease that worsens over time.

  • Perimenopausal brain fog is temporary and linked to hormonal changes, sleep disruption, and stress.

  • A 2023 UK study found perimenopausal women report poorer reaction time, visual memory, and attention compared to premenopausal women. These changes are part of the transition, not early dementia.

  • Research shows that a woman’s lifetime estrogen exposure is actually protective for long-term brain health.

What Can Help With Brain Fog?

While brain fog can’t always be eliminated, there are strategies that support better cognition and brain health:

  • Prioritize sleep: Aim for consistent bedtime routines and cool sleep environments.

  • Exercise regularly: Aerobic and strength training support brain-derived neurotrophic factor (BDNF), a protein that promotes learning and memory.

  • Eat for your brain: A Mediterranean-style diet rich in plants, whole grains, fish, and healthy fats has been linked to better cognitive aging.

  • Manage stress: Techniques like mindfulness, journaling, or therapy can reduce the cognitive load.

  • Consider treatment: Menopause hormone therapy (MHT) doesn’t necessarily reverse brain fog, but when started early, it doesn’t worsen cognition — and it may help indirectly by improving sleep or mood.

Read my blog on osteoporosis prevention to learn more about estrogen’s role in long-term health.

When to Seek Support

If memory changes are persistent, worsening, or affecting daily life, it is worth consulting a healthcare provider. Brain fog is usually temporary, but it should never be dismissed if it is causing distress or interfering with your quality of life.

The Bottom Line

Brain fog in perimenopause is common, real, and often temporary. It reflects the brain’s response to hormonal shifts, sleep changes, and stress — not the start of dementia.

You’re not alone if you feel your mind isn’t as sharp during this stage. With the right support, most women find their cognitive clarity improves over time.

I’m Dr. Madeleine Clark, ND and Menopause Society Certified Practitioner. I help women navigate PMS, PMDD, perimenopause, and menopause with evidence-based, compassionate care.

Book an appointment today if brain fog, fatigue, or mood changes are impacting your daily life — so you can feel like yourself again.

hormonal health, menopause, perimenopause, mental wellnessMadeleine Clark