GHK-Cu vs Matrixyl
GHK-Cu (Copper-binding tripeptide) and Matrixyl (Cosmetic signal peptide) are documented as co-studied in the PeptiDex library. This page puts the two entries side by side on class, molecular weight, half-life, origin, mechanism and studied research areas — every value taken from the entry it belongs to.
Why these two are co-studied
Cross-referenced for research context — not a usage or combination recommendation.
At a glance
| Attribute | GHK-Cu | Matrixyl |
|---|---|---|
| Compound class | Copper-binding tripeptide | Cosmetic signal peptide |
| Research category | Cosmetic & Dermal | Cosmetic & Dermal |
| Length (amino acids) | 3 amino acids | 5 amino acids |
| Molecular weight | 340.4 Da | ~802 Da |
| Half-life | Not documented | Not documented |
| Origin | GHK is a naturally occurring tripeptide (glycyl-L-histidyl-L-lysine) found in human plasma, with levels reported to decline with age. GHK-Cu is its complex with copper(II) ions and is widely used as a cosmetic ingredient. | Matrixyl is a trade name for palmitoyl pentapeptide-4 (INCI; formerly palmitoyl pentapeptide-3), a lipidated matrikine peptide developed by Sederma for topical anti-aging cosmetics. Related products include Matrixyl 3000 and Matrixyl synthe'6, which use different peptide combinations. |
“Not documented” means the PeptiDex entry records no value for that field. Nothing on this page is estimated, and no figure is carried over from one compound to the other.
How GHK-Cu works
GHK has a high affinity for copper(II) and is understood to act partly as a copper-delivery molecule, facilitating copper transport relevant to enzymatic and remodeling processes. In cell and skin research it has been associated with signaling that influences extracellular-matrix remodeling, collagen and glycosaminoglycan synthesis, and antioxidant and gene-expression effects. Much of this work is from in-vitro and skin studies.
How Matrixyl works
Matrixyl couples a matrikine pentapeptide (KTTKS, a fragment derived from type I collagen) to a palmitoyl group that improves skin penetration. The KTTKS motif is proposed to act as a signal fragment that stimulates fibroblasts to increase synthesis of extracellular matrix components such as collagen and glycosaminoglycans. This 'matrikine signaling' is the basis of its cosmetic use to improve skin firmness and reduce fine-line appearance.
Mechanistic descriptions reflect published research-literature understanding and are quoted from each compound's own entry. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
Where each one appears in the literature
The research contexts each entry documents. Listing a research area is not a claim of efficacy or a therapeutic indication, and the two lists are not scored against each other.
GHK-Cu
Matrixyl
What sets each apart
GHK-Cu
GHK-Cu is the most established copper tripeptide in cosmetic use, distinguished from AHK-Cu by its sequence and from repair peptides like BPC-157 by its remodeling and copper-delivery focus.
Matrixyl
Matrixyl works via matrikine collagen-stimulation signaling rather than the neurotransmitter/SNARE modulation attributed to Argireline and SNAP-8.
Frequently asked questions
What is GHK-Cu?
GHK-Cu is a complex of the naturally occurring tripeptide GHK (glycyl-L-histidyl-L-lysine) with a copper(II) ion. The GHK sequence is a subfragment of the alpha-2 chain of type I collagen and is present in human plasma, where its level declines with age. It is studied primarily as a copper-delivery and skin-remodeling signal peptide.
What is GHK-Cu studied for?
In research and cosmetic-formulation literature it is studied for collagen and glycosaminoglycan synthesis in dermal fibroblasts, wound-model remodeling, and antioxidant/gene-modulating activity. It is characterized as a signaling peptide rather than a therapeutic drug, and is not FDA-approved for treating any condition.
Why is a higher GHK-Cu concentration not necessarily better?
Research summaries note a biphasic dose response: GHK-Cu stimulates matrix synthesis at low (picomolar to nanomolar) concentrations, but at higher concentrations it can also upregulate matrix-degrading enzymes. This is why most cosmetic formulation guidance centers on the low end of the topical range rather than maximizing concentration.
What is Matrixyl?
Matrixyl (palmitoyl pentapeptide-4, Pal-KTTKS) is a topical cosmetic lipopeptide consisting of the pentapeptide KTTKS (a fragment of type I procollagen) conjugated to a palmitic-acid chain that improves skin penetration. It is used as a collagen-signaling anti-aging ingredient.
How does Matrixyl work?
The KTTKS motif is a fragment released during collagen breakdown that acts as a feedback signal to fibroblasts. In cell-culture research, Pal-KTTKS has been reported to stimulate synthesis of collagen and extracellular-matrix components such as fibronectin, which underlies its use in skin-firming formulations.
What topical concentration of Matrixyl is used?
The effective range cited is roughly 10-100 ppm of pure peptide (about 0.001%-0.01%). The foundational clinical study used pal-KTTKS at 100 ppm (0.01%) versus vehicle, indicating biological activity even at very low concentrations.
Answers are the ones published on each compound's own PeptiDex entry. They are educational summaries of research-literature context and are not medical advice.