l-theanine and glutathione (Standard) (L-Glutamic Acid γ-ethyl amide (Standard)) | Neuroprotective Agent NOW Supplements, Glutathione 250 mg,

Yes, it is FDA approved

I highly recommend testing your NAD levels to see where your levels are at and how much they need to be optimized

For example, peptides, especially when injected, may trigger severe immune responses

Hou Y, Dan X, Babbar M, Wei Y, Hasselbalch SG, Croteau DL, Bohr VA (2019) Ageing as a risk factor for neurodegenerative disease

The coding region was cloned into a modified pETM-11 bacterial expression vector (EMBL Heidelberg) which was derived from a pET-24d(+) vector (Novagen) by insertion of a tobacco etch virus (TEV) protease cleavage site following a N terminal hexa-histidine and protein A tag