Frequently asked questions
What is GHK-Cu?
GHK-Cu is the copper(II) complex of the tripeptide glycyl-L-histidyl-L-lysine. On a cosmetic ingredient list it appears under its INCI name, Copper Tripeptide-1, and its listed cosmetic function is as a skin conditioning agent.
Why is GHK-Cu blue?
The colour belongs to the copper(II) ion held by the peptide rather than to the peptide itself. In the preparation described in the cosmetic safety literature, the purified complex is collected as the chromatography fraction identified by its visible-light absorbance, and crystallised material is described there as dark purple-blue. The absorbance wavelength is given in the appearance entry.
Is GHK-Cu a drug?
No. It is used as a cosmetic ingredient, and the cosmetic safety review lists its function as skin conditioning. Nothing on this site should be read as a claim that GHK-Cu acts on any disease or medical condition.
What does the published human research actually show?
Very little that is decisive. The randomised human comparison cited here found no objective between-group difference, and the other published human report on facial appearance cited here is a single-patient case using a mixture of several actives at once. Read the limitations section before drawing conclusions from anything else on this site.
What does the published work say about GHK-Cu's stability?
One preformulation study put the complex through forced-degradation testing. It remained stable in water and in mildly acidic to neutral buffers held at an elevated temperature for two weeks, and degraded under basic and oxidative stressors, and less so under acidic stress. That measures degradation kinetics under deliberate stress. The published literature does not establish handling or shelf-life conditions for a finished product.
Does copper from GHK-Cu get into skin?
In laboratory diffusion cells using excised human skin, copper applied as the tripeptide complex both crossed the tissue and was retained in it. That is a model run under continuous exposure, and it is not a measurement of what a finished cosmetic does on intact living skin.
What has the cosmetic safety review concluded?
The Cosmetic Ingredient Review expert panel concluded that copper tripeptide-1 is safe in the present practices of use and concentration in cosmetics. The panel reached that conclusion having noted the low use concentrations together with the safety test data it reviewed, so the conclusion is stated for those practices of use and concentration.
What concentration of copper tripeptide-1 do cosmetics use?
The cosmetic safety review does not set a figure; it reports what industry told it. An industry survey returned a range of use concentrations across the peptide ingredients the review covered, and a separate industry submission reported a customary level for peptides generally. Both figures, and the caveat that the survey range is collective across those ingredients rather than specific to copper tripeptide-1, are given in the use concentration entries; compare them there. Concentration on its own also says nothing about whether the copper complex in a given product is intact, which is what a lot-specific certificate of analysis is for.