AHK-Cu: The Copper Tripeptide Studied for Hair Follicles
A copper-binding tripeptide related to GHK-Cu, with research skewed toward hair-follicle and scalp effects rather than general skin remodeling.
What is AHK-Cu (Copper Tripeptide-3)?
AHK-Cu (copper tripeptide-3) is a copper-binding tripeptide — alanine-histidine-lysine complexed with a copper ion — structurally related to the better-known GHK-Cu but studied with a research emphasis on hair-follicle and dermal-papilla stimulation rather than general skin remodeling. Its regulatory situation has two distinct halves: cosmetic-grade topical AHK-Cu, sold in serums and scalp products, is regulated as a cosmetic ingredient and doesn't require premarket drug approval. Injectable or microneedling-delivered AHK-Cu sold by research-peptide vendors is a separate, unapproved research chemical, not intended for human use.
Quick facts
- Molecular Formula
- C15H25ClCuN6O4 (hydrochloride form)
- Molecular Weight
- 452.40 g/mol
- CAS Number
- 682809-81-0 (hydrochloride form)
- Class
- Copper-binding tripeptide (Ala-His-Lys-Cu)
- Brand Names
- No trademarked brand — sold as a cosmetic ingredient (topical) or research compound (injectable)
- Legal Status
- Topical form: regulated as a cosmetic ingredient, no premarket approval required. Injectable/research form: not FDA-approved for human use — research use only (RUO)
- Category
- Skin & Hair
- Storage
- Store the lyophilized vial refrigerated (2-8°C) or at -20°C, away from light. Once reconstituted, keep refrigerated at 2-8°C and use promptly.
Dosing at a glance
For the injectable/research vial form: a common convention is a 50mg vial + 5mL bacteriostatic water. Topical cosmetic products require no reconstitution. Run the numbers in the reconstitution calculator.
Doses shown are those reported in published research, not a recommendation.
AHK-Cu (Copper Tripeptide-3) Mechanism of Action
A Hair-Focused Cousin of GHK-Cu
AHK-Cu is a copper-binding tripeptide (Ala-His-Lys complexed with Cu2+), structurally distinct from GHK-Cu despite the similar naming convention and shared copper-peptide category. Where GHK-Cu's research base is broad (skin remodeling, wound healing, collagen synthesis), AHK-Cu's research is more specifically oriented toward hair follicle and scalp effects.
Dermal Papilla and Growth Factor Signaling
Research on AHK-Cu centers on stimulation of dermal papilla cells — the signaling hub at the base of hair follicles that regulates the hair growth cycle — alongside collagen synthesis and general tissue-regeneration effects broadly similar in category to copper-peptide biology overall, driven by copper-dependent upregulation of growth factors and matrix remodeling.
AHK-Cu (Copper Tripeptide-3) Dosage and Protocols
Form-Dependent Use
Topical cosmetic serums specify a formulated concentration rather than an injectable dose, applied per product label directions. For the injectable/research vial form sold by peptide vendors, no standardized clinical dose exists — informal research protocols vary considerably vendor to vendor.
AHK-Cu (Copper Tripeptide-3) Side Effects and Safety
Form-Dependent Risk Profile
Topical cosmetic use is generally well tolerated, with rare mild skin irritation reported. The injectable/research form carries the same general uncharacterized-risk profile as other unapproved research peptides — no formal human safety trial exists for that route. Known copper-metabolism disorders (e.g. Wilson's disease) and pregnancy are treated as precautionary contraindications for the injectable/research form.
AHK-Cu (Copper Tripeptide-3) Research Evidence
Cosmetic Industry vs. Research-Peptide Evidence
Most published evidence on AHK-Cu comes from cosmetic-industry and in-vitro dermal-papilla-cell research, funded largely by cosmetic ingredient suppliers, rather than independent clinical trials. This is a different evidence pathway than pharmaceutical drug development, and claims should be weighed accordingly — a cosmetic ingredient can be legally marketed without FDA drug-style efficacy trials.
Regulatory and Legal Status
AHK-Cu's legal status depends entirely on the form sold. Topical AHK-Cu, used in cosmetic serums and scalp products, is regulated as a cosmetic ingredient and does not require FDA premarket drug approval. Injectable or microneedling-delivered AHK-Cu, sold by research-peptide vendors, is a separate, unapproved research chemical — not approved for human use in that form, and sold RUO. Don't conflate the two: a legally-sold cosmetic serum and an unapproved injectable research vial are regulated completely differently.
AHK-Cu (Copper Tripeptide-3) Stacking and Combinations
AHK-Cu + GHK-Cu
AHK-Cu is commonly paired with GHK-Cu in skin and hair research protocols — combining AHK-Cu's hair-follicle-oriented research with GHK-Cu's broader, better-studied skin-remodeling and collagen effects.
AHK-Cu (Copper Tripeptide-3) Pharmacokinetics
No Established Systemic PK Profile
No formal human pharmacokinetic study exists for AHK-Cu in either form. Topical use is designed for local, not systemic, exposure, so a conventional plasma half-life isn't the relevant metric; for the injectable/research form, systemic pharmacokinetics remain uncharacterized.
Contraindications
- pregnancy (injectable/research form)
- known copper sensitivity or Wilson's disease
Frequently asked questions
What is a typical AHK-Cu (Copper Tripeptide-3) dose?
Published research protocols report Topical: per-serum concentration · Injectable: no standardized dose, varies by form. This is the range described in the literature, not a recommendation.
Is AHK-Cu (Copper Tripeptide-3) backed by strong evidence?
AHK-Cu (Copper Tripeptide-3) carries a REGEN research grade of D. REGEN Research Tier D — in-vitro and small cosmetic studies only, with no controlled clinical outcome.
How is AHK-Cu (Copper Tripeptide-3) administered?
Routes reported in the literature: topical, subcutaneous.
Who should avoid AHK-Cu (Copper Tripeptide-3)?
Contraindications noted in the literature include pregnancy (injectable/research form), known copper sensitivity or Wilson's disease.
References
- The effect of tripeptide-copper complex on human hair growth in vitro · Pyo HK, Yoo HG, Won CH · 2007