During the perimenopause to menopausal transition women can experience preservation of cognitive functions to mild disruption in cognitive domains to severe cognitive disorders. Two thirds of women report cognitive disruption during the menopausal transition. Menopause-associated disruption of cognitive function can recover, persist or worsen following the transition. Estrogenic control of cognitive function, from the molecular to structural standpoint, is well documented and replicable across preclinical and clinical studies. In contrast, both observational and interventional clinical studies of menopausal hormone therapy (MHT) and its impact of cognitive function have yielded variable outcomes ranging from beneficial to neutral to detrimental. Key factors influencing the impact of MHT are stage of the menopausal transition when MHT is initiated and its formulation. MHT initiated early in the menopausal transition has the strongest evidence for sustaining cognitive function and reducing Alzheimer’s risk. In contrast, administration of MHT after the menopausal transition is associated with increased risk of cognitive disorders, such as Alzheimer’s. The formulation of MHT, particularly the progestogen component, is a key factor in determining impact on cognitive function. Continuous combined estrogen and progestin therapies increase the risk of cognitive decline, whereas an estrogen alone or episodically administered with a progestogen are likely to exert benefit on cognitive function. MHT containing natural steroids, 17β-estradiol and/or progesterone were associated with greatest reduction in risk of age associated neurodegenerative diseases. If effective, MHT can sustain existing level of cognitive function. Precision MHT to sustain cognition is key to sustaining women’s brain health and cognitive function.