One reason for this is that the level of glutathione will fluctuate throughout the day from its lowest in the early morning to depletion from routine exposure to toxic substances (like alcohol), pathogens, cigarette smoke, car exhaust, drugs, certain foods, stress level, illness, and many similar factors, so repeated testing could be required to set a baseline
My bottom line (and the honest truth) The best glutathione lightwieght face serum isnt the one with the loudest claims, its the one youll actually use daily because it feels good, layers well, and keeps your skin calm
While both are antioxidants, NAC supports the production of glutathione, whereas glutathione acts directly to protect the body
It absorbs almost instantly but leaves a lovely glow I may have oily skin but Im not a fan of my skincare instantly turning matte