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GHK-Cu

Also known as Copper peptide, Copper Tripeptide-1, GHK-copper, Glycyl-L-histidyl-L-lysine copper.

Best known for Skin renewal and collagen support

Evidence★★☆☆☆

Safety datawell-characterised (topical) / poorly characterised (injected)

Route topical · injectable (not supported)

United StatesTopical cosmetic: lawful. Injectable: not approved

AustraliaTopical cosmetic: lawful. Injectable: Schedule 4

as at 16 September 2026

What it is

GHK-Cu is a very small peptide: three amino acids (glycine, histidine, lysine) bound to a copper ion. It occurs naturally in human plasma, where levels decline with age, and it has been used in skincare for decades. On an ingredients list it usually appears as Copper Tripeptide-1.

It stands out in this book for two reasons: it has human trial evidence for topical use, and it exists as two very different products, a lawful cosmetic and an unapproved injectable, which are often discussed as though they were the same thing.

What the full entry covers

The book carries the rest of this entry:

Where the research stands, with every claim cited
What people commonly ask, and what the research shows so far
Dosing in four labelled bands, described and not recommended
Side effects, serious risks, cautions and interactions
Questions to discuss with your doctor
How it compares with AHK-Cu, Matrixyl, Argireline, BPC-157

Related entries

AHK-CuThe copper peptide for hair rather than skin · Evidence ★★☆☆☆
MatrixylOne of the best-evidenced cosmetic peptides · Evidence ★★★☆☆
ArgirelineThe expression-line peptide often called "topical Botox" · Evidence ★★★☆☆
BPC-157Tendon, joint and gut repair · Evidence ★★☆☆☆

A certificate of analysis tells you what is in a vial. The evidence rating above tells you whether the compound has been shown to work in humans. Neither answers the other's question. How to read a certificate of analysis.

This page describes what is known and not known about GHK-Cu. It is not medical advice and not a recommendation to use it.