Brain fog symptoms can occur at any stage throughout perimenopause and menopause. “How long it lasts varies from patient to patient,” says Dr. Arumala. The good news is that menopause brain fog is usually temporary. Once your hormone levels settle, your cognitive function should return to normal. “Most women will notice that their verbal memory is most affected during perimenopause and that it improves and can return to baseline two to three years after menopause,” adds Dr. Homaifar.