During aging, metabolic function gradually declines, leading to insulin resistance, fat accumulation, and insufficient energy metabolism
[153] There is evidence that for elderly people, physicians often repeatedly prescribe and administer cyanocobalamin injections inappropriately, evidenced by the majority of subjects in one large study either having had normal serum concentrations or having not been tested before the injections
For recreational fitness enthusiasts who are not subject to drug testing, this restriction does not apply, but it is worth knowing
NNMT, nicotinamide N-methyltransferase, is found throughout the body but is particularly active in fat tissue
The safety profile of topical GHK-Cu is well-established across decades of use and multiple clinical trials