Its well-studied for replenishing glutathione levels (its even the hospital antidote for acetaminophen overdose!) (StatPearls)
Sonobe H, Takeuchi T, Furihata M, Taguchi T, Kawai A, Ohjimi Y, et al
A naturally occurring delta-EEG enhancing nonapeptide in urine of sleep-deprived rabbits
[50] [276] In the first step, a reaction between phenylacetone and formamide, either using additional formic acid or formamide itself as a reducing agent, yields N -formylamphetamine
References : [1] [3] [4] [5] [6] National Library of Medicine, Regenerative and Protective Actions of the GHK-Cu Peptide in the Light of the New Gene Data, Pickart, L., Margolina, A., July 2018 [2] National LIbrary of Medicine, The potential of GHK as an anti-aging peptide, Dou, Y., Lee, A., Zhu, L., Morton, J., Ladiges, W., March 2020
(4) Regenerating other antioxidants like vitamin C and vitamin E after they've been oxidised