This article covers all of it: how GHK-Cu affects hair follicle biology, what the studies actually show, how topical and injectable forms compare, and how it fits into a serious multi-modal hair protocol
Additionally, it is important to correct cobalamin deficiency before starting folic acid treatment, or provide cyanocobalamin together with folic acid
That rule is a heuristic, not a biological law
It reflects deeper biological processes hormones, inflammation, sun exposure, and internal balance
This feature supports extended use without rapid contamination risks
Now the big ethical debate: when supply is tight, who gets priority