What it is
GHK-Cu is a naturally occurring tripeptide, glycyl-L-histidyl-L-lysine, bound to a copper ion. It occurs naturally in the body and is studied for wound healing, collagen synthesis, skin rejuvenation, and hair growth. Its combination of a small peptide backbone and a bound metal ion is part of what makes GHK-Cu unusual among the compounds discussed on this site, most of which are peptides alone.
In the PeptidesAI encyclopedia it is categorized under skin and anti-aging, and it is discussed both as a topical (skin-applied) ingredient and as a compound studied by subcutaneous (under-the-skin) route.
How it's thought to work
GHK-Cu is studied for stimulating the synthesis of collagen and glycosaminoglycans, structural components of skin and connective tissue, and for promoting the proliferation of stem cells. It is also studied for anti-inflammatory effects and for supporting wound healing through enzymatic pathways that depend on its bound copper, which is thought to be central to how the peptide activates these repair processes.
What the research says
Human studies support topical (applied to the skin) use of GHK-Cu for skin healing. Subcutaneous (under-the-skin injection) use has been studied less formally, though the evidence base for that route is described as growing rather than as established as the topical research.
Reported side effects
Reported side effects are minimal. Injection site irritation is possible. A notable and harmless finding is that reconstituted GHK-Cu solution turns blue, a normal result of the copper ions in the molecule rather than a sign of a problem. No serious adverse effects are described in the available material.
Reconstitution
GHK-Cu is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted with bacteriostatic (BAC) water before use. It commonly comes in 50 mg, 100 mg and 200 mg vials. The amount of peptide in the vial is fixed; the water added only changes how concentrated the solution is.
Worked example. A 50 mg vial is 50,000 mcg. Reconstituted with 5 mL of BAC water, that works out to 50,000 mcg ÷ 5 mL = 10,000 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, each unit holds 10,000 × 0.01 = 100 mcg. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
The one distinctive handling note for GHK-Cu is that the solution turning blue after reconstitution is expected and normal, not a sign the product has degraded or was prepared incorrectly. It is not FDA-approved as an injectable product.
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is GHK-Cu?
A naturally occurring copper-binding tripeptide studied for wound healing, collagen synthesis, skin rejuvenation, and hair growth.
How is GHK-Cu thought to work?
It is studied for stimulating collagen and glycosaminoglycan synthesis, promoting stem cell proliferation, and supporting wound healing through copper-dependent pathways.
What does the research on GHK-Cu say?
Human studies support topical use for skin healing; subcutaneous use has a smaller but growing evidence base.
What are the reported side effects of GHK-Cu?
Minimal, with occasional injection site irritation. Reconstituted solution turning blue is normal and expected, not a problem.
How much is one unit from a 50 mg GHK-Cu vial?
With 5 mL of BAC water, a 50 mg vial is 10,000 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 100 mcg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for GHK-Cu — one of 70 compounds covered — plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
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