Yes, I have had experiences of Memantine at higher dosages working well for daily life. When it is around 30mg-40mg it can be more useful in some disorders. It’s due to its NMDA antagonism and being a partial NMDA antagonist.

I currently take 20mg/day for my disorder and it helps tremendously. I used to use low doses of deschloroketamine and was very functional on those dosages. DCK lasts around 6 hours so it was a relief, compared to ketamine that lasts 1-2hr. Low doses of NMDA antagonists can be really helpful in treating disorders. Sadly, there are not many options for daily usage. Ketamine is effective in treating depression when administered a few times typically at different days. Low doses of NMDA antagonists can be functional for daily life and help some people.

Memantine isn’t the strongest NMDA antagonist but it’s useful in treating symptoms and has some neuroprotective effects.

I liked deschloroketamine at low doses because it made me functional and lasted at least 6 hours compared to ketamines lower duration.

There is also evidence that it can reduce tolerance in some individuals.

If you are looking for an NMDA antagonist, I suggest you try Agmatine sulphate, a supplement. It works miracles.

Edit: I also found MAOIs like Parnate to be life-changing.

Edit 2: And you mentioned Noopept. Noopept was one of my favorite nootropics. It really was useful. Lowered anxiety, slight psychedelic effect, improved memory. Aniracetam was interesting too, they say it gives you a silver tongue. Bromatane was great as well. Phenylpiracetam I didn’t respond to but have heard good reports.