glutathione brain benefits in Our Diet and Its Role in the Body: From Disease Prevention to Anti-Aging Brain Glutathione Levels Associate With

You should start seeing the benefits of Glutathione around three weeks into treatment

Xu C, Sun L, Ren F, et al

After being boosted through precursor supplementation, NAD+ often plateaus and declines around week 12, which is likely due to an overabundance of NAM (a byproduct of NAD+) and a shortage of methyl donors present to fuel conversion in the salvage pathway.38 Supplementing with a potent methyl donor can offset this shortage and ensure sustained activity in the salvage pathway

Experimental & Molecular Medicine (2016) 7

Furthermore, the depletion of GSH has been widely shown to exacerbate oxidative stress and oxidative modifications of molecules [3537]