In the case of AHK, the copper atom is linked between the alanine and histidine residues of the alanine-histidine-lysine peptide
Genetics of skin, hair, and eye color in human pigmentation disorders
reconstituted solutions are commonly stored colder for longer-term integrity (per internal methods)
1998;1:136-141 Leyden J, Stephens T, Finkey MB, Appa, Y, Barkovic S, Skin Care Benefits of Copper Peptide Containing Facial Cream
The recommended vitamin B12 intake (in micrograms, or mcg) is as follows: *Adequate Intake S ource: National Institutes of Health Office of Dietary Supplements Unless you have a B12 deficiency or have identified a risk factor for deficiency (like following a vegan diet or having a malabsorption issue), theres no need to take a vitamin B12 supplement
2017 Cell study used 5 mg/kg intraperitoneal injection three times per week in aged mice, with treatment periods of several weeks the three-times-weekly dosing suggests the peptide maintains sufficient functional concentrations for at least 48-72 hours per dose (PMID: 28340339)