What is GHK-Cu used for?

What it is being studied for

• Facial wrinkles (topical serum): wrinkle volume 55.8% lower than a plain vehicle serum and 31.6% lower than a commercial Matrixyl 3000 product after 8 weeks in 40 women; a human randomized trial, double-blind and split-face, published in a journal not indexed in PubMed [1]
• Skin after CO2 laser resurfacing (topical): no difference between groups in redness resolution or wrinkle improvement; patients rated overall skin quality higher with GHK-Cu (P=.04); a small human randomized trial, 13 completers [2]
• Hair loss (scalp injection): hair-pull test improved in 83% of 1,000 patients, but the injected formulation also held five growth factors, so GHK-Cu’s part cannot be separated; a human study with no control group [3]
• Wound healing: in rabbits, topical copper tripeptide wounds filled with new tissue in 14 vs 25 days (mean healing 29.8 vs 34.6 days); in rats, more glycosaminoglycans, a skin-matrix building block, in wound chambers; animal studies [4][5]
• Ligament graft healing: rats injected in the knee after ACL reconstruction had less knee laxity at 6 weeks (p=0.009) but no difference at 12 weeks; an animal study [6]
• Lung injury and lung scarring: lower inflammatory signals (TNF-alpha, IL-6) in mice with induced lung injury, and less scarring in mice with induced fibrosis; animal studies [7][8]
• Alzheimer’s-type changes: 5xFAD mice given GHK-Cu in the nose 3 times a week for 3 months showed delayed memory decline and fewer amyloid plaques; an animal study [9]
• No human study of injected, intranasal or oral GHK-Cu on its own was found.

How it works

1. Copper carrier: GHK (glycine-histidine-lysine) was isolated from blood and found bound to roughly equal amounts of copper; its discoverer proposed that it helps cells take up copper [10][11].
2. Skin-matrix building: in cultured human skin cells (fibroblasts) GHK-Cu raised collagen and elastin output and stimulated sulfated glycosaminoglycan production [1][12][13].
3. Tissue remodelling: it shifted the balance of matrix-cutting enzymes (MMPs) and their blockers (TIMPs) in skin cells, and in rat wounds it raised MMP-2 and kept MMP-9 present longer [1][14].
4. Inflammation: in mice and mouse immune cells it lowered reactive oxygen species, TNF-alpha and IL-6 through the NF-kB and p38 pathways, and in lung scarring it acted on the TGF-beta1/Smad pathway [7][8].
5. What sets it apart: it is a copper complex that crosses skin; in a laboratory test a 0.68% copper tripeptide solution moved copper through human skin samples [15], and in a head-to-head trial it reduced wrinkle volume more than a commercial cosmetic peptide product [1].

Adverse events reported

• Topical wrinkle trial: 39 of 40 women tolerated the serums over 8 weeks; one had minor skin reactions on both sides of the face (GHK-Cu and comparator), stopped, and recovered without medical treatment [1].
• Post-laser trial: the published abstract reports no adverse-event data [2].
• Scalp-injection combination study: the authors reported that treatment was well tolerated [3].
• No safety data for injected or systemic GHK-Cu on its own in people were found.

Forms

Topical GHK-Cu is the only form tested on its own in people, in two small trials [1][2]. Injected into the scalp it appears only inside a multi-ingredient formulation [3]; injections into the knee, the abdomen or wound chambers were studied in rats and mice [5][6][8]. Intranasal GHK-Cu has one mouse study [9], and no oral study was found.

For how topical and injected GHK-Cu compare, see GHK-Cu topical vs injection.