• Posted September 1, 2026

Hormone Therapy With Estriol Might Relieve Menopause 'Brain Fog'

Hormone therapy might help women experiencing “brain fog” during menopause, a new small-scale study says.

Menopausal women struggling with memory lapses, trouble concentrating and slower thinking benefited from hormone therapy combining estriol and progesterone, researchers report today in the journal Scientific Reports.

“Estrogen plays a well-documented role in protecting the brain, yet there are still no approved type and dose of treatment that specifically targets the cognitive symptoms so many women experience during menopause,” said senior researcher Dr. Rhonda Voskuhl, a neurologist with the Comprehensive Menopause Center at UCLA Health.

“Women are often told to simply live with brain fog, when in fact there is a neuroscience basis for it, and potentially a way to address it,” Voskuhl said in a news release. “That gap in care is what motivated us to look more closely at estriol.”

Estriol is a natural form of estrogen that occurs during pregnancy, researchers said in background notes. It has been used in Europe and Asia to treat menopause symptoms, and targets a different estrogen receptor in the brain than estradiol, the most common estrogen hormone therapy in the United States.

Currently, estriol is not approved by the U.S. Food and Drug Administration and is only available as a compounded medication in the United States.

Previous research has suggested that estriol might play a role in protecting brain cells and reducing shrinkage in the hippocampus, the brain region responsible for learning and memory.

For this pilot study, researchers followed 20 menopausal women with an average age of 53. The women received combination treatment with estriol and progesterone for one year to see how the therapy would affect their brain fog.

After the treatment, participants reported significant improvements in brain fog, concentration, working memory, processing speed, verbal memory and problem-solving, researchers said.

Experiments with female lab mice supported these results. When treated with estriol, the mice had less deterioration in the hippocampus and better brain performance on tests.

Researchers noted that this was a pilot study and that further research is needed before estriol’s benefits can be confirmed. Larger trials involving brain imaging and cognitive testing are the next step, the team said.

More information

Harvard Medical School has more on hormone therapy for menopause.

SOURCE: UCLA, news release, Sept. 1, 2026