AHK-Cu: Scientific Profile

Publicado el 12 de julio de 2026

AHK-Cu (CAS 682809-81-0) is a copper tripeptide formed by the sequence Ala-His-Lys complexed with a copper (II) ion, related to Pickart's GHK-Cu. Its proposed mechanism centers on the delivery of bioavailable copper and signaling in follicular and dermal cells. Material intended exclusively for research use.

AHK-Cu is a copper peptide complex belonging to the family of copper tripeptides, the same class of cosmetic molecules whose prototype is GHK-Cu (glycyl-L-histidyl-L-lysine:copper) originally described by Loren Pickart. The molecule is composed of the tripeptide L-alanyl-L-histidyl-L-lysine (Ala-His-Lys, abbreviated AHK) coordinated with a copper (II) ion. In international cosmetic nomenclature it is designated Copper Tripeptide-3. Its chemical identity corresponds to CAS number 682809-81-0, with molecular formula C15H24CuN6O4 and an approximate molecular weight of 415.94 g/mol. The key structural difference relative to GHK-Cu is the substitution of the N-terminal glycine residue with alanine, a conservative change that maintains the overall architecture of the peptide but slightly modifies its charge, hydrophobicity, and coordination affinity for copper.

From a structural standpoint, the most important functional feature of this family of molecules is the copper-binding motif. The histidine residue, through the nitrogen of its imidazole ring, together with the terminal amino group and the amide nitrogen of the chain, forms a high-affinity chelation site for copper (II). This capacity to sequester and transport copper in a soluble and relatively stable form is what distinguishes the copper tripeptides from ordinary peptides and what underpins the mechanistic hypotheses that have been explored in research models. Copper is an essential cofactor of numerous metalloenzymes —among them lysyl oxidase, copper-zinc-dependent superoxide dismutase, and enzymes involved in melanin synthesis and angiogenesis—, so the local availability of copper is a relevant factor in the processes of extracellular matrix remodeling and tissue turnover that are studied in vitro.

The mechanism of action of AHK-Cu is not as thoroughly characterized as that of GHK-Cu, and much of what is proposed is inferred by analogy within the class. The dominant hypothesis is that the complex acts as a shuttle for bioavailable copper into cells, delivering the ion to copper-dependent enzymatic and signaling systems. In preclinical and cell-culture studies, copper tripeptides have been associated with the modulation of the expression of extracellular matrix components, such as collagen and glycosaminoglycans, and with growth factor signaling. In the specific case of AHK-Cu, much of the interest in cosmetic research has focused on models related to the hair follicle: its effect on dermal papilla cells and on angiogenic markers such as vascular endothelial growth factor (VEGF) has been explored within experimental systems seeking to understand the biology of the hair cycle. It is worth emphasizing that these are laboratory contexts and that the mechanistic readouts come from in vitro and preclinical models, not from a consolidated body of clinical trials.

The documented research applications of AHK-Cu are situated almost entirely in the experimental cosmetic and dermatological field. It is an ingredient that appears in topical research formulations oriented toward the study of skin and hair, and it is usually employed at very low concentrations owing to its nature as a copper complex. The most frequent lines of research include: the study of signaling in dermal papilla cells and keratinocytes; the evaluation of extracellular matrix synthesis markers in fibroblasts; and the exploration of properties related to skin appearance in models of cutaneous aging. Because of its kinship with GHK-Cu, it is often compared with it in experimental panels that seek to differentiate the behavior of different copper tripeptides. In all these cases, the framework of use is strictly that of a reagent for research and formulation development, not that of a product with established therapeutic indications.

As for the level of evidence, it is important to be honest and prudent. GHK-Cu, the best-studied member of the family, has decades of literature and numerous studies in biochemistry and cell biology. AHK-Cu, by contrast, is considerably less characterized: the available evidence is mostly preclinical, in vitro, and tied to cosmetic applications, and there is no robust, independent clinical support to justify strong efficacy claims. It should not be interpreted as a compound with an approved therapeutic use or with demonstrated medical properties. Any extrapolation of its effects observed in cell cultures to whole biological systems must be made with caution and within the experimental context.

With regard to its handling, AHK-Cu is usually presented as a powder, typically of a bluish or blue-violet color characteristic of copper complexes. As a reagent, it is sensitive to degradation and its stability depends on pH, on the presence of competing chelating agents, and on exposure to light and heat. In a laboratory setting it is handled with the usual precautions for peptide metal complexes, avoiding contamination with reducing or oxidizing agents that could alter the state of the copper. In summary, AHK-Cu is a copper tripeptide of interest in cosmetic and dermatological research, whose appeal derives from its ability to coordinate copper and from its structural kinship with GHK-Cu, but whose evidence profile remains limited and predominantly preclinical. All of its use corresponds exclusively to the research domain.