A scientific review of four small-scale studies confirmed that glutathione use does result in some skin lightening.24 Additionally, glutathione has also been shown to decrease psoriasis when levels are bolstered by intake of whey protein, which contains glutamylcysteine, a precursor to GSH.25 Most impressively, perhaps the same studies mentioned above also show that glutathione doesn't just lighten, but it improves skin elasticity and decreases wrinkles' appearance
Leucht S, Cipriani A, Spineli L, Mavridis D, Orey D, Richter F, et al
Particle size distribution: The polydispersity index (PDI) measures the uniformity of particle sizes
The dermis, the middle layer of skin where collagen and elastin reside, begins thinning as early as our late twenties