Cosmetic peptide
GHK-Cu copper peptide
GHK-Cu is a copper-binding tripeptide (glycyl-histidyl-lysine bound to copper). Discovered by biochemist Loren Pickart in 1973, it is the most-studied cosmetic peptide, with a body of in-vitro and topical human research supporting collagen synthesis, skin barrier repair and antioxidant activity. In the UK it is regulated as a cosmetic ingredient (not a medicine) and appears in serums from brands stocked at Cult Beauty, LookFantastic, Space NK and Boots. PeptideClear compares formulations by concentration and pairing.
What concentration matters
Most published topical research uses 0.1% to 1% GHK-Cu. UK consumer serums typically sit in the 0.05% to 0.3% range when concentration is disclosed. "Contains copper peptides" without a concentration usually means trace amounts in a base of other ingredients.
INCI position is the proxy when concentration is not disclosed. If "copper tripeptide-1" appears in the top 8 ingredients, the concentration is meaningful. If it appears in the bottom third of a long INCI list, the concentration is trace.
UK serums we track
v0.2 will publish a side-by-side table of 12-15 UK GHK-Cu serums with INCI position, declared concentration where available, and our verdict. Click through to purchase fires our affiliate link.
- · The Ordinary Multi-Peptide + Copper Peptides 1% (Cult Beauty, Boots)
- · Niod CAIS 2 (Cult Beauty)
- · Medik8 Liquid Peptides (LookFantastic, Cult Beauty)
- · Asterwood Naturals copper peptide serum (Amazon UK)
- · Skin Biology Super Cop (specialist UK importers)
- · Allies of Skin Triple Hyaluronic Acid + Copper Peptides (Cult Beauty)
What pairs and what does not
- · Pairs well with: hyaluronic acid, niacinamide (in separate steps), peptide blends like Matrixyl, ceramides.
- · Pairs poorly with: vitamin C (low pH degrades the peptide), strong AHAs in the same step, retinoids in the same step.
- · Layering rule: copper peptides at one step, vitamin C or retinoid at a different step or different time of day.
Where to buy GHK-Cu copper peptide serums in the UK
We are applying to affiliate programmes at Cult Beauty, LookFantastic, Boots, Beauty Pie and Space NK. Once approved, verified product rows with affiliate-tracked links will appear here.
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Buy UK peptide skincare
Compare UK retailers and brands stocking peptide skincare. Editorial selection independent of commercial arrangements.