I’m confused. Where does one get Menin? And why buy Nestle’s Celltrient site sells GlyNAC in packets of 600 mg glycine and 600 mg NAC, as “Cellular Protect,” ??? Is it a precursor to Menin that the body makes?
Both D-serine and L-serine (the commonly available form of serine) help multiple processes we need, including manufacture of glycine and cysteine in our bodies. However, L-serine conversion to D-serine is lacking in older people.
Since you can't easily find D-serine and L-serine appears to not work correctly, you can at least supplement glycine and cysteine, which are also required in our bodies and also are no longer being properly made in our bodies. Supplementing glycine and cysteine has already been proven to greatly benefit older people.
So you can get a good amount of benefit from what is commonly available, even if you can't find what is not commonly available.