What is GHK-Cu? A plain-English explainer
A three-amino-acid peptide that binds a copper ion, first identified in human plasma and now used mainly as a topical cosmetic ingredient.
GHK-Cu is a copper-binding tripeptide — a chain of just 3 amino acids (glycine, histidine, and lysine) holding onto a copper ion — that occurs naturally in human plasma. It was first isolated from human blood plasma in 1973 and has since been formulated in two very different ways: as a topical cosmetic ingredient, and as a separate lyophilised research form. It is not an approved drug in either case.
That one paragraph is the whole definition. The rest of this page unpacks it at two levels — plain English, then a little deeper — and covers the reconstitution math for the research form specifically, because that form ships as a dried powder that has to be mixed and measured before anything else.
GHK-Cu in plain English
GHK-Cu is only 3 amino acids long — glycine, histidine, lysine, which is where the name “GHK” comes from — making it a tripeptide, one of the shortest peptides in common use. The “Cu” is the chemical symbol for copper, and it refers to the copper ion the peptide naturally binds.
It isn’t a purely synthetic invention. Researcher Loren Pickart identified it in human plasma in 1973 while studying differences between blood from younger and older donors, and it’s still measurable in the body today, in saliva and urine as well as plasma, with levels that vary by age.
Two very different products share this name. One is a topical cosmetic form — creams and serums that list “copper tripeptide-1” on the ingredient panel, regulated as a cosmetic rather than a drug. The other is a lyophilised (freeze-dried) powder sold and studied as a research chemical, typically reconstituted and measured with a syringe. These are not interchangeable, and this page’s reconstitution section is about the powder form, not the cream.
The science, a little deeper
A few specifics that the plain-English version glosses over:
- It’s a defined 3-amino-acid sequence with a bound metal ion. GHK-Cu is glycyl-L-histidyl-L-lysine complexed with a copper(II) ion — a specific, characterised small molecule, not a mixture or an extract.
- It’s naturally occurring, but the products are made in a lab. The peptide backbone is identical to what circulates naturally in human plasma, but cosmetic and research-grade GHK-Cu are manufactured synthetically for consistency and purity.
- Regulatory status depends on the form. Cosmetic ingredients like copper tripeptide-1 don’t require FDA pre-approval before sale, which is why it appears in many over-the-counter products. The separate injectable/research form is not on the FDA’s approved bulk substance lists for compounding and is not an approved medicine for any condition.
If you want the classification in one line: GHK-Cu is a naturally occurring copper-binding tripeptide, 3 amino acids plus a copper ion, available as a topical cosmetic ingredient and, separately, as a freeze-dried research powder for reconstitution.
How reconstitution works for GHK-Cu
This section is about the lyophilised research powder, not the topical cream — creams are applied directly and are not reconstituted. Reconstitution is dissolving the powder in a known volume of liquid so you have a concentration — milligrams of peptide per millilitre of solution. Once the concentration is fixed, the volume you draw for any target amount is simple arithmetic:
- Concentration = vial amount (mg) ÷ diluent volume (mL)
- Draw volume = target amount ÷ concentration
- Syringe units = draw volume (mL) × the units-per-mL of your syringe
The numbers all come from your own vial label and your own paperwork — the peptide amount printed on the vial, the volume of diluent you add, and the target amount you were told to use. The separate Amidra web calculator runs exactly those three steps and shows the formula at each one, so you can check it by hand. It never fills in a number for you.
What Amidra does — and doesn’t — do here
Amidra is a tracking and education tool. It converts the values you enter and helps you keep a protocol organised; it does not recommend a dose, a compound, or a schedule, and it takes no position on whether anyone should use GHK-Cu in any form. Those decisions belong with a qualified healthcare professional. The information above is definitional — what the compound is and how its two common forms differ — not medical advice.