AHK-Cu
A synthetic copper-chelating tripeptide (Ala-His-Lys) positioned as the hair-follicle-focused cousin of GHK-Cu, researched for follicle stimulation and scalp vascularity.
AHK-Cu is a synthetic copper(II)-complexed tripeptide composed of alanine, histidine, and lysine, structurally related to but distinct from the better-known GHK-Cu. It is researched primarily for hair follicle stimulation, VEGF-mediated angiogenesis at the dermal papilla, and collagen/elastin support, and is used chiefly in topical cosmetic hair formulations. Preclinical and cosmetic-grade evidence exists for its follicle effects, but formal RCT-grade human data specific to AHK-Cu is limited, and it is not FDA-approved for any therapeutic indication.
Class
Synthetic copper-chelated tripeptide (Ala-His-Lys + Cu2+)
Half-life
Unknown; short free-peptide plasma half-life, with copper-complex stability and topical penetration being the relevant pharmacokinetic properties in cosmetic use.
Routes
Topical, Subcutaneous, Intradermal (mesotherapy)
Category
Skin, Hair & Cosmetic
Researched benefits
What it's studied for
Hair follicle stimulation
Preclinical and cosmetic-grade studies suggest AHK-Cu stimulates hair follicle dermal papilla cells and growth-factor signaling (including proposed Wnt/beta-catenin and anagen-phase activation), supporting hair density and shaft diameter when applied topically. Evidence tier: preclinical/cosmetic, with modest effect sizes.
Scalp vascularity via VEGF
The peptide is proposed to upregulate vascular endothelial growth factor (VEGF), increasing dermal papilla microvascularization and blood supply to the follicle. Evidence tier: preclinical.
Reduced follicle miniaturization
In androgenetic alopecia models, AHK-Cu has been associated with reduced follicle miniaturization, a core driver of pattern hair thinning. Evidence tier: preclinical models.
Collagen and elastin support
By delivering bioavailable copper, a cofactor for lysyl oxidase, AHK-Cu can support collagen and elastin crosslinking and maturation, contributing to wound-healing and dermal remodeling. Evidence tier: mechanistic/preclinical.
Antioxidant cofactor activity
Copper delivered by the tripeptide serves as a cofactor for superoxide dismutase, contributing antioxidant support in dermal and follicular tissue. Evidence tier: mechanistic.
Complement to GHK-Cu in scalp formulations
AHK-Cu is positioned as the hair-follicle-targeted copper tripeptide, often formulated alongside GHK-Cu in multi-peptide scalp products for combined follicular and dermal effects. Evidence tier: cosmetic formulation experience; formal synergy trials lacking.
Mechanism
How it works
AHK-Cu is a copper-chelated tripeptide in which alanine, histidine, and lysine bind a copper(II) ion, with histidine providing the primary chelation site — the same structural motif that underlies GHK-Cu's activity. The alanine substitution at position 1 (versus glycine in GHK) confers different tissue specificity and pharmacokinetics, shifting the compound's emphasis from broad skin regeneration toward hair follicle biology.
The peptide's central proposed action is delivery of bioavailable copper ions to follicular and dermal tissue. Copper serves as a cofactor for several key enzymes: lysyl oxidase (collagen and elastin crosslinking), superoxide dismutase (antioxidant defense), and pathways involved in vascular endothelial growth factor (VEGF) signaling. This links AHK-Cu to both structural dermal remodeling and angiogenesis.
At the hair follicle, AHK-Cu is proposed to act on dermal papilla cells and follicular stem cells, promoting keratinocyte proliferation, activating the anagen (growth) phase, and increasing microvascular blood supply through VEGF-mediated angiogenesis. Some preclinical comparisons suggest AHK-Cu has stronger follicle-stimulating activity than GHK-Cu, though the two remain distinct compounds rather than interchangeable substitutes.
Pharmacokinetically, the free peptide has a short plasma half-life; in cosmetic use the relevant properties are the stability of the copper complex and topical penetration, which allow the tripeptide backbone to carry copper into the skin. Systemic absorption through intact skin is very low, which underlies the compound's low topical risk profile.
Dosing protocols
Dosing & administration
Dosing reflects protocols reported in research and community literature for educational purposes. It is not medical advice or a recommendation. Most peptides here are not approved for human use.
Reconstitution
For research-grade lyophilized powder used to prepare topical formulations, the material is typically dissolved and incorporated into a serum or carrier base at low concentrations; copper content and ratio should be verified. No standardized systemic reconstitution protocol is established.
Topical (Cosmetic)
- Dose
- Low-percentage formulation (irritation reported above ~1%)
- Frequency
- Once daily
- Timing
- Applied to scalp/skin, typically after cleansing
- Duration
- Ongoing cosmetic use
- Route
- Topical
The primary and best-supported use. Incorporated into hair-growth serums, often alongside minoxidil or other actives. Keep concentration modest to avoid scalp irritation.
Intradermal (Mesotherapy)
- Dose
- Not standardized in the source material
- Frequency
- Per practitioner protocol
- Timing
- In-office administration
- Duration
- Course-based
- Route
- Intradermal
Used in cosmetic compounding/mesotherapy for scalp treatments targeting follicle miniaturization. No validated numeric protocol is published; practitioner-directed only.
- Topical application is the primary and best-evidenced route; there is no legitimate, validated protocol for systemic injection of AHK-Cu.
- Common research vial sizes are 50 mg and 100 mg, with raw powder also sold for DIY topical formulation.
- Effect sizes for hair growth are modest and well below those of minoxidil or finasteride; AHK-Cu is best viewed as a cosmetic adjunct rather than a standalone alopecia therapeutic.
- Copper ratio and identity should be independently verified, since the copper-complexed form is pharmacologically distinct from the free peptide and mislabeling occurs.
Combinations
Stacking & blends
AHK-Cu + GHK-Cu Copper Peptide Stack
Combined follicular and dermal regeneration in scalp/skin formulations
AHK-Cu targets hair follicle biology while GHK-Cu provides broader skin regeneration; cosmetic products frequently combine both copper tripeptides, though formal combination trials backing specific synergy are lacking.
AHK-Cu + Minoxidil Hair Adjunct
Support hair density and follicle stimulation alongside an FDA-approved agent
AHK-Cu acts through copper/VEGF/follicle pathways distinct from minoxidil's vasodilator/K+-channel mechanism, making it a plausible topical cosmetic adjunct to minoxidil; most human evidence for AHK-Cu comes from such combination formulations.
Safety
Side effects & considerations
Commonly reported effects
Contraindications & cautions
- Known copper hypersensitivity or disorders of copper metabolism (e.g., Wilson's disease) — theoretical caution with sustained copper exposure
- Systemic/injectable use is not established and is discouraged outside research settings
Topical AHK-Cu is generally well tolerated at cosmetic concentrations, with very low absorption through intact skin and no systemic toxicity documented at topical doses. As with GHK-Cu, the copper content raises a theoretical concern about copper accumulation with sustained high-dose use, though clinically meaningful copper toxicity has not been reported. Long-term safety at sustained research-use injectable dosing is not well characterized, and GHK-Cu safety data does not automatically transfer to AHK-Cu.
FAQ
AHK-Cu — common questions
What is AHK-Cu?
AHK-Cu is a tripeptide-copper complex (alanine-histidine-lysine bound to copper) developed as a companion compound to GHK-Cu, targeted specifically at hair follicle biology. It is the less-researched sibling in the copper-peptide family.
What does AHK-Cu do?
Preclinical and cosmetic-industry studies suggest AHK-Cu stimulates hair follicle dermal papilla cells and supports hair-growth signaling, VEGF-mediated scalp vascularity, and collagen maturation. Human clinical evidence is limited and typically involves combination topical formulations.
How is AHK-Cu administered?
Topical application is the primary use, incorporated into hair-growth serums and cosmetic formulations, sometimes via intradermal mesotherapy. There is no legitimate protocol for systemic injection, and cosmetic products typically use low concentrations.
How does AHK-Cu compare to GHK-Cu?
Both are copper-transporting tripeptides sharing a histidine-mediated chelation motif, but AHK-Cu is positioned for hair follicles while GHK-Cu is the far more heavily researched skin-regeneration peptide. AHK-Cu inherits GHK-Cu's 'copper peptide' reputation but has a much thinner dedicated evidence base.
How does AHK-Cu compare to minoxidil?
They work through fundamentally different mechanisms — AHK-Cu via copper, VEGF, and follicle stimulation; minoxidil via vasodilation and potassium-channel opening. Minoxidil is FDA-approved for hair loss with Phase 3 evidence, whereas AHK-Cu has only preclinical and cosmetic-use evidence with modest effect sizes.
Is AHK-Cu FDA approved?
No. AHK-Cu has no FDA drug approval. It is classified as a cosmetic ingredient and is legal in hair-care and skincare products, while raw/injectable material is sold as a research-use-only compound.
What are the side effects of AHK-Cu?
Topical AHK-Cu is well tolerated at cosmetic concentrations, with occasional mild scalp or skin irritation and possible temporary discoloration from copper. Systemic effects are uncommon given the topical use pattern, and no systemic toxicity has been documented at topical doses.
Can AHK-Cu and GHK-Cu be used together?
Cosmetic formulations sometimes combine both copper tripeptides, and combined topical use is incorporated into commercial products. Combined injectable research-use protocols vary and are not validated; anyone considering combined use should consult a licensed physician.
