for others, it may take up to 90 days to notice any visible results
Kurutas et al
Still, a few risks deserve attention: Absolute contraindications: Wilson's disease or any other copper metabolism disorder, active cancer (because of GHK-Cu's pro-angiogenic activity), pregnancy, and breastfeeding
References: Glutathione and Parkinsons Disease: Glutathione metabolism in type 2 diabetes and its relationship with microvascular complications and glycemia Glutathione supplementation improves oxidative damage in experimental colitis Application of Glutathione as Anti-Oxidative and Anti-Aging Drugs Differentiating Sulfur Compounds Sulfa Drugs, Glucosamine Sulfate, Sulfur, and Sulfiting Agents by Subhuti Dharmananda, Ph.D., Director, Institute for Traditional Medicine, Portland, Oregon
In both cases, neutralization according to these definitions can be measured in in vitro assays
1990, pp