Copper Tripeptide-3

Copper Tripeptide-3 (AHK-Cu) is a synthetic tripeptide-copper complex consisting of alanine, histidine, and lysine (Ala-His-Lys) chelated to a copper(II) ion. It is chemically and structurally distinct from Copper Tripeptide-1 (GHK-Cu, glycyl-L-histidyl-L-lysine copper complex), also built on this site, despite the similar INCI naming convention and the shared presence of a histidine-lysine copper-binding motif in both molecules.

At Verified Peptides, we want to directly flag this naming structure since it is a genuine, non-obvious source of confusion in this exact catalog: INCI 'Copper Tripeptide' names are numbered sequentially (Copper Tripeptide-1, -2, -3, etc.) to distinguish different specific copper-peptide complexes, similar to how 'Palmitoyl Tripeptide-1' and 'Palmitoyl Pentapeptide-4' (both also built on this site) are distinct fatty-acid-conjugated peptides despite overlapping naming conventions. Researchers should not assume shared research findings between differently numbered Copper Tripeptide compounds.

Chemically, Copper Tripeptide-3 (free base) has molecular formula C15H24CuN6O4, molecular weight approximately 415.94 g/mol (independently cross-calculated from the formula's atomic composition, matching vendor-reported figures), CAS number 767286-83-9. A hydrochloride salt form is also commercially available (CAS 682809-81-0, formula C15H25ClCuN6O4, MW approximately 452.40 g/mol) — we confirmed both figures independently via atomic-mass calculation before including them here. PubChem CID 169450582.

We cross-checked both the free-base and hydrochloride-salt molecular weights independently, atom by atom, rather than accepting a single vendor's figure at face value: for the free base (C15H24CuN6O4), summing 15 carbon (12.011 each), 24 hydrogen (1.008 each), 1 copper (63.546), 6 nitrogen (14.007 each), and 4 oxygen (15.999 each) yields approximately 415.94 g/mol, matching vendor-reported figures. For the hydrochloride salt (C15H25ClCuN6O4), the same atom-by-atom approach — adding one hydrogen and one chlorine atom relative to the free base — yields approximately 452.40 g/mol, again matching the vendor figure. This manual cross-check is part of our standing practice of independently verifying numeric chemical claims rather than repeating unverified vendor figures, a practice that has previously caught a real vendor data error on a different compound in this catalog.

At Verified Peptides, we think Copper Tripeptide-3's evidence base is genuine but narrow, resting substantially on a single, real, peer-reviewed study rather than a broad or independently replicated literature. The 2007 Pyo et al. study (PMID 17703734, Archives of Pharmacal Research, volume 30, issue 7, pages 834-839) is the compound-specific research we can confidently cite, and it used a combination of ex vivo human hair follicle organ culture and in vitro dermal papilla cell assays — both are legitimate, commonly used models in hair-growth peptide research, though ex vivo organ culture and cultured-cell proliferation assays are not the same as a controlled human clinical trial measuring actual scalp hair density or count over time.

We want to be direct about a citation-verification issue we identified and are deliberately not resolving by fabrication: several commercial and vendor sources describe a supposed 2021 randomized controlled trial in the journal Dermatologic Surgery directly comparing topical AHK-Cu against 5% minoxidil in human subjects with androgenetic alopecia, with specific reported hair-density figures. We were unable to independently verify that this specific trial exists in any indexed, searchable primary source, and the specificity of the reported statistics without a locatable publication is a pattern we treat as a red flag rather than a citation we can respect. We are not including this claimed trial in this profile's research_papers list, and researchers evaluating vendor marketing claims for this compound should apply the same scrutiny. We think this specific case illustrates a broader pattern worth naming directly: a claim that includes a specific journal name, year, sample size, and numeric outcome can read as more credible than a vague claim, even when the underlying study cannot actually be located anywhere. Precision of detail is not, by itself, evidence of a claim's truth, and we treat unlocatable specific-sounding claims as a reason for additional scrutiny rather than reduced scrutiny.

Similarly, a claimed 2023 King's College London study on topical AHK-Cu penetration depth into scalp tissue, cited on some vendor and blog sites, could not be independently located in a searchable, indexed primary source during this research process, and is likewise not included here. At Verified Peptides, we would rather cite one real, verifiable study than pad a profile with claims we cannot confirm. No FDA, EMA, or other Western regulatory body evaluates Copper Tripeptide-3 as a drug, since it is regulated as a cosmetic ingredient. We sell research-grade Copper Tripeptide-3 exclusively for laboratory research.

The INCI 'Copper Tripeptide' naming series (Copper Tripeptide-1 through at least Copper Tripeptide-3, and additional numbered variants used by some manufacturers) reflects a broader cosmetic-ingredient naming convention in which sequentially numbered names are assigned to structurally related but chemically distinct copper-peptide complexes as they are registered, rather than indicating generations or improved versions of a single compound. Researchers and buyers should treat each number as its own distinct chemical entity requiring its own citation trail.

Unlike GHK-Cu, which has an extensive independent research history spanning more than three decades across wound healing, dermal remodeling, and general anti-aging cosmetic science, AHK-Cu's published research is comparatively concentrated in the specific context of hair follicle and dermal papilla cell biology, reflecting its primary commercial positioning as a hair-growth-focused cosmetic active rather than a general-purpose anti-aging ingredient.

Both the free-base and hydrochloride salt forms of Copper Tripeptide-3 are sold commercially, with the hydrochloride salt form typically favored for improved aqueous solubility in cosmetic formulation work — a common pattern across many peptide-based cosmetic actives, where a salt form is preferred for practical formulation reasons even when the underlying bioactive complex is identical.

Copper's role as a trace element cofactor extends well beyond any single peptide complex — it is required for the normal function of lysyl oxidase, an enzyme that cross-links collagen and elastin fibers in skin and other connective tissue, which is part of why copper delivery in general (not any one specific copper-peptide compound) has been a longstanding area of interest in dermatological and wound-healing research. Tripeptide-copper chelation, as used in both AHK-Cu and GHK-Cu, is one specific strategy among several for delivering bioavailable copper to target tissues in a controlled, chelated form rather than as a free ionic species, which can be more reactive and less selectively targeted.

At Verified Peptides, we require independent third-party HPLC purity testing and mass spectrometry identity confirmation for every batch of research-grade Copper Tripeptide-3 we offer, with a Certificate of Analysis (COA) available for each lot. Because Copper Tripeptide-3 is a metal-peptide complex, identity confirmation should verify both the peptide sequence and correct copper coordination, not the free peptide sequence alone.

We source exclusively from manufacturers operating under Good Manufacturing Practice (GMP)-aligned quality systems, and every lot is independently verified rather than accepted solely on a supplier's internal documentation. Researchers should always request and review the specific COA for the lot they receive, confirming both purity percentage and molecular identity, including which specific form (free base or hydrochloride salt) is represented, before use in any experimental protocol.

Lyophilized Copper Tripeptide-3 is stable when stored at -20°C, protected from light and moisture. At Verified Peptides, we ship lyophilized peptide with appropriate cold-chain packaging to preserve stability in transit.

As a copper-peptide complex, Copper Tripeptide-3 shares general handling considerations with other copper-chelated peptides in this catalog, including GHK-Cu — copper complexes can be sensitive to light-driven redox degradation over extended storage, so opaque or light-protected packaging and minimizing freeze-thaw cycles after reconstitution are both reasonable precautions.

Once reconstituted, solution should be stored refrigerated at 2–8°C and used within the timeframe indicated on the product's documentation.