There is no reliable way to test potency at home, so your results will tell you whether the peptide is still effective
Step 6: Draw out the same volume of air that you've injected (10 mL) from the Methylcobalamin 10,000 mcg vial before pulling the needle out

According to a 2018 review, GHK-Cu as a cosmetic ingredient has demonstrated the ability to:3 Tighten loose skin Reverse age-related skin thinning Repair the skins protective barrier proteins Improve skin firmness and elasticity Reduce the appearance of fine lines and wrinkles Smooth rough skin Stimulate wound healing Lessen the appearance of photodamage (sun damage), hyperpigmentation, skin spots, lesions, and more Reduce inflammation and damage from free radicals Increase hair growth and thickness Additionally, in research from 2015, the authors noted that GHK-Cu may be able to stimulate collagen, regulate the skin remodeling process, attract immune cells to the site of an injury, and restore replicative vitality to fibroblasts (a cell that helps form connective tissue) in patients whove undergone radiation therapy for cancer.2 6 GHK-Cu isnt limited to topical/cosmetic forms, however
The tri-peptide GHK-Cu complex ameliorates lipopolysaccharide-induced acute lung injury in mice
Rigorous clinical trials of injected GHK-Cu are scarce
Because the moment they proved it worked, every grey-market lab on earth would sell the exact same molecule, at a fraction of the price, having spent nothing