Skin Health

Most of them act as signals. Skin peptides are short chains of amino acids that tell skin cells to make more of what young skin is rich in, mainly collagen and elastin, the proteins that keep skin firm and springy. Production of both slows with age, so peptides are researched as a way of nudging those building processes back into gear. GHK-Cu is the most studied peptide in this category and the reference point for skin peptides generally.

GHK-Cu is a small peptide made of three amino acids, glycine, histidine, and lysine, which give it the GHK, attached to a copper ion, which gives it the Cu. It occurs naturally in the human body and has been studied since the 1970s, making it one of the longest researched peptides in any category. Most of that research concerns skin repair and regeneration, which is why it is the best known peptide in skin health.

Skin repair, in the broadest sense. GHK-Cu is researched for supporting collagen and elastin production, skin firmness and elasticity, and the skin's ability to heal, and it is also studied for calming inflammation in skin. Its earliest research was in wound healing rather than cosmetics. Few peptides in any category have been studied for as long, which is why GHK-Cu turns up everywhere from research papers to serum labels.

They come at skin aging from different directions. Retinol is a form of vitamin A that speeds up skin cell turnover, encouraging older surface cells to shed and newer ones to replace them. GHK-Cu works on the rebuilding side instead, signaling skin to produce more of its own collagen and elastin. One resurfaces, the other reinforces, which is why the two come up in the same conversations without really being rivals.