2. Anti-epileptic, promote sleep.
3. Beauty moisturizing, delay brain aging function.
4. Lower blood pressure effect.
5. Regulate immune function.

Memantine is used to treat moderate-to-severe Alzheimer's disease, especially for people who are intolerant of or have a contraindication to AChE (acetylcholinesterase) inhibitors.One guideline recommends memantine or an AChE inhibitor be considered in people in the early-to-mid stage of dementia.
Memantine has been associated with a modest improvement; with small positive effects on cognition, mood, behavior, and the ability to perform daily activities in moderate-to-severe Alzheimer's disease. There does not appear to be any benefit in mild disease.
Memantine when added to donepezil in those with moderate-to-severe dementia resulted in "limited improvements" in a 2017 review. The UK National Institute of Clinical Excellence (NICE) issued guidance in 2018 recommending consideration of the combination of memantine with donepezil in those with moderate-to-severe dementia. Effects in autism are unclear. Recent scientific journal reports are showing guarded promise with severe obsessive compulsive disorder.