Head to head
Both are copper-binding tripeptides and both get filed under "copper peptides for skin," but the actual studies behind them look at different tissues and, in GHK-Cu's most recent case, a different combination product entirely.
GHK-Cu is a naturally occurring copper-binding tripeptide studied for roles in skin remodeling, antioxidant activity and extracellular matrix support. A 2026 study reported results for GHK-Cu combined with a bacterial ferment extract, not GHK-Cu tested alone, which limits how directly that result applies to a single-ingredient GHK-Cu product.
AHK-Cu (L-alanyl-L-histidyl-L-lysine copper complex) was studied directly in an ex vivo human hair follicle organ culture and in cultured human dermal papilla cells. That is a narrower application, aimed at hair rather than general skin, but the study design tested the compound itself rather than a combination product.
General skin remodeling and hair follicle biology are related but distinct research questions. Choosing GHK-Cu for a hair-related goal, or AHK-Cu for a general skin goal, extends each compound's evidence past what was actually measured.
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Repair and tissue research
GHK-Cu is best supported as a topical cosmetic ingredient studied in dermatology research; it is not an FDA approved drug for injectable use. Cosmetic-grade topical products and supplier research-chemical vials are different formulations and are not interchangeable based on the sources reviewed.
Read the research →Repair and tissue research
AHK-Cu is a distinct tripeptide-copper complex, structurally related to but not identical to GHK-Cu. It is not an FDA approved drug. The primary study identified used ex vivo human hair follicle organ culture and in vitro dermal papilla cell culture, not living human subjects or an animal model.
Read the research →Reign Peptide · Business disclosure
Jorge Abreu is involved in Reign Peptide. Links to Reign are a business connection, not an independent endorsement. Reign lists these products for laboratory research, not human consumption.
Use the listing to check the labeled identity, amount and available batch documentation. A purity result alone does not verify sterility, clinical suitability or equivalence to a medicine used in a trial.
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