Thanks The Nice guidelines are for NHS prescriptions and based on cost saving re hydroxocobalamin as it was costed in the 1980's
The amount of thickening agent depends on the nature and the concentration of the other ingredients and in general ranges from about 0.5 to 1.5%, and in particular is approximately 1.5%
doi:10.1097/JU.0000000000002007.04
This immune decline, called immunosenescence, contributes to higher infection rates, slower healing, and reduced cancer surveillance in older adults
However, like many peptides, GHK-Cu does not easily cross this barrier
Journal of Cosmetic Dermatology , 20(3), 893900