What is the GHK-Cu peptide?
GHK-Cu is a small peptide made of three amino acids (glycine, histidine and lysine) attached to a copper ion. It occurs naturally in human blood, saliva and urine, and is often just called “copper peptide.”
You’ll also see the GHK-Cu peptide written as “GHK Cu peptide,” “GHKCU peptide” or just “GHK”; they mean the same thing (GHK is the peptide without its copper).
It was discovered in 1973 by Loren Pickart, who found it in human blood. Levels in the blood fall with age, which is one reason it became popular in anti-aging skin care.
What does GHK-Cu do?
In lab and animal studies, GHK-Cu helps skin repair itself. It encourages skin cells to make collagen and other support proteins, attracts cells involved in healing and has antioxidant and anti-inflammatory effects.
That is why it shows up in two places: skin care, as a serum or cream, and wound-healing research. More recently, some clinics and online sellers have started offering it as an injection.
Do GHK-Cu peptide serums work?
The evidence for creams and serums is real but limited. Several small controlled studies on faces have found less visible wrinkling and firmer skin after a few months of use, but the studies are small and short.
Like other peptides, copper peptides are fairly large molecules for skin to absorb, so how well a product works depends on its formula. Like any active ingredient, it can irritate some people’s skin; a patch test on a small area first is sensible.
Is injectable GHK-Cu safe?
There are no good human trials of GHK-Cu injections, so their safety and benefits are unknown. The evidence that exists comes from skin products and from animals.
Products sold online for injection are research chemicals that nobody checks for purity, strength or contamination. Doctors also note that copper levels in the body need to stay in balance.
Is GHK-Cu legal?
GHK-Cu is legal and widely sold as a skin care ingredient. As an injection it is not an approved medicine.
In April 2026 the nominations for injectable GHK-Cu were withdrawn, so it moved off the FDA’s list of compounding substances with safety concerns (Category 2). That is not an approval, and the FDA has said it plans to ask its advisory committee about GHK-Cu.
How do you reconstitute GHK-Cu?
Injectable GHK-Cu comes as a blue powder that is mixed with bacteriostatic water. The calculator above turns the vial size, the water and a dose into syringe units, and the reconstitution guide explains each step.
See the dosage section below for what is known about doses, with sources.