ghk cu tolerance desensitization long term use effectiveness loss The tri-peptide GHK-Cu complex ameliorates lipopolysaccharide-induced acute lung injury in mice Glycyl‐l‐histidyl‐l‐lysine‐Cu2+ rescues cigarette smoking‐induced skeletal
Description
Head-to-head data are sparse
"Two concentrations of topical tretinoin (retinoic acid) cause similar improvement of photoaging but different degrees of irritation: a double-blind, vehicle-controlled comparison of 0.1% and 0.025% tretinoin creams." Archives of dermatology 131.9 (1995): 1037-1044
That does not invalidate the findings, but it is relevant context for how to interpret them [19]
As for homocysteine, levels may rise not just in the absence of B12, but in the absence of B6 and folate as well
