Most formulators know GHK-Cu. Far fewer know its copper peptide sibling — AHK-Cu. That gap represents a significant opportunity, because AHK-Cu does something GHK-Cu doesn’t, and the two together create a copper peptide synergy that no single-peptide formula can replicate.
This guide covers AHK-Cu in full: its mechanism, specifications, formulation requirements, and why it belongs in any serious anti-aging or skin-regeneration stack.
What Is AHK-Cu?
AHK-Cu is the abbreviation for Copper Tripeptide-3 — the tripeptide Ala-His-Lys complexed with a copper ion (Cu²⁺). Like its more famous counterpart GHK-Cu (Copper Tripeptide-1), AHK-Cu is a naturally occurring tripeptide found in human plasma, but it has a distinct amino acid sequence and a distinct primary mechanism of action.
Where GHK-Cu is primarily known for collagen and elastin stimulation, AHK-Cu is defined by its angiogenic activity — its ability to promote the formation of new blood vessels and capillaries in the dermis. This makes it uniquely valuable for formulations targeting skin density, circulation, scalp health, and under-eye treatment.
INCI Name: Copper Tripeptide-3 (Alanine/Histidine/Lysine Polypeptide Copper HCl) CAS: 130120-57-9 Molecular Weight: 396.87 g/mol Solubility: Water-soluble
The Mechanism: Angiogenesis and Beyond
AHK-Cu works through several pathways that distinguish it from other copper peptides:
Angiogenesis — AHK-Cu promotes the growth of new microcapillaries in the dermis. Improved vascular density means better nutrient delivery, improved oxygenation, and more efficient waste removal at the cellular level. This translates to visibly improved skin tone, reduced dullness, and enhanced radiance over time.
Fibroblast activation — Like GHK-Cu, AHK-Cu stimulates fibroblast proliferation and collagen synthesis, contributing to improved skin firmness and elasticity.
Wound healing support — AHK-Cu has been studied for its role in accelerating tissue repair, making it valuable in post-procedure and barrier-recovery formulations.
Hair follicle support — The angiogenic pathway is particularly relevant for scalp applications. Improved blood flow to hair follicles supports the delivery of nutrients essential for healthy hair growth, making AHK-Cu a compelling active in scalp serums and hair loss treatments.
Anti-inflammatory activity — The copper ion complex modulates inflammatory signaling, calming irritation and redness at the dermal level.
Product Specifications
| Parameter | Specification |
|---|---|
| Compound | Copper Tripeptide-3 |
| CAS | 130120-57-9 |
| Purity | ≥99% HPLC verified |
| Form | Lyophilized powder |
| Appearance | Blue-green powder |
| Solubility | Water-soluble |
| Recommended pH | 4.0 – 7.0 |
| Suggested use level | 1% – 5% |
| Storage | 2–8°C, sealed, away from light |
Note the blue-green appearance — this is characteristic of copper-complexed peptides and is expected. It will impart a faint blue-green tint to water-phase formulations at higher concentrations, which can be a desirable visual cue of copper peptide activity or managed through formula design.
AHK-Cu vs GHK-Cu: Understanding the Difference
The question formulators most often ask is: which copper peptide should I use? The answer is both — but here’s how they differ:
| GHK-Cu | AHK-Cu | |
|---|---|---|
| Primary mechanism | Collagen/elastin stimulation | Angiogenesis, vascular density |
| Secondary activity | Anti-inflammatory, wound healing | Fibroblast activation, hair support |
| Best for | Anti-aging, barrier repair, firmness | Radiance, circulation, density, scalp |
| Appearance | Blue-green powder | Blue-green powder |
| Use level | 1%–5% | 1%–5% |
| pH range | 4.0–7.0 | 4.0–7.0 |
Combined at 1%–2% each, GHK-Cu and AHK-Cu create a comprehensive copper peptide complex that addresses collagen synthesis, skin density, vascular health, and inflammation simultaneously — a formulation that no single copper peptide can achieve alone.
How to Formulate With AHK-Cu
Dissolution
AHK-Cu is water-soluble. Dissolve in distilled or deionized water before adding to your formulation. The blue-green color is normal and expected.
Phase Addition
Add to the water phase or during cool-down below 40°C. Avoid high heat which can degrade the copper-peptide complex.
pH Considerations
AHK-Cu is stable between pH 4.0 and 7.0. Keep your finished formulation within this range. Avoid combining with strong alkaline ingredients that would push pH above 7.5.
Copper Peptide Interactions
Do not combine copper peptides with high-concentration vitamin C (ascorbic acid) — ascorbic acid can reduce and destabilize the copper ion, degrading both actives. Vitamin C derivatives (ascorbyl glucoside, sodium ascorbyl phosphate) are generally more compatible at moderate concentrations.
Three Formulation Concepts
1. Dual Copper Peptide Radiance Serum
GHK-Cu 2% + AHK-Cu 2% in a hyaluronic acid base with niacinamide 3% and panthenol 1%. This is the copper peptide power couple — collagen stimulation plus angiogenesis, delivered in a lightweight serum that improves both texture and radiance.
2. Scalp Revitalizing Treatment
AHK-Cu 3% + Biotin 0.1% + Caffeine 1% in an alcohol-free scalp serum base. The angiogenic pathway makes AHK-Cu particularly suited to scalp applications where blood flow to follicles is the primary target.
3. Under-Eye Repair Complex
AHK-Cu 2% + PDRN 1% + GHK-Cu 1% + Caffeine 0.5% in a fluid eye serum base. This combination addresses the three primary causes of under-eye aging simultaneously — poor microcirculation (AHK-Cu), tissue thinning (GHK-Cu), and fluid retention (caffeine) — while PDRN supports overall tissue regeneration.
Compatibility Guide
Pairs well with:
- GHK-Cu — complementary copper peptide mechanisms
- PDRN — tissue regeneration and brightening
- Niacinamide — tone-evening and barrier support
- Hyaluronic acid — hydration foundation
- Caffeine — circulation synergy for scalp and eye applications
- Panthenol — soothing and barrier repair
Use with caution:
- High-concentration ascorbic acid — can degrade copper ion
- High pH ingredients — destabilizes complex above pH 7.5
- Strong chelating agents like high-concentration EDTA
Dosage Reference
| Serum Size | 1% | 2% | 3% |
|---|---|---|---|
| 30ml | 0.30g | 0.60g | 0.90g |
| 50ml | 0.50g | 1.00g | 1.50g |
| 100ml | 1.00g | 2.00g | 3.00g |
A 1g sample lot produces multiple test batches at working concentrations — ideal for initial formulation development before scaling up.
Why AHK-Cu Is Underused — And Why That’s Changing
AHK-Cu has historically been overshadowed by GHK-Cu simply because GHK-Cu came first and accumulated more published research. But the formulation community is catching up. Formulators building sophisticated multi-peptide complexes increasingly recognize that angiogenic activity is a distinct and valuable mechanism that GHK-Cu alone doesn’t provide.
As consumer awareness of copper peptides grows beyond the basics, AHK-Cu is positioned to become a differentiating ingredient — the mark of a formulator who understands the nuance between copper peptides, not just their general category.
Source Your AHK-Cu
We supply AHK-Cu (Copper Tripeptide-3) at 99% HPLC-verified purity in gram-scale lots through to bulk kilogram quantities. Every lot ships with a Certificate of Analysis. Available from 1g sample lots for initial formulation testing up to 1kg for production runs.
Browse our full copper peptide range including GHK-Cu alongside AHK-Cu, and contact us for bulk pricing on 100g+ orders.
For volume pricing contact us at sales@uspowders.com or submit a bulk inquiry.
For cosmetic formulation use only. Not for human consumption or injection. All USPowders products are research-grade cosmetic actives intended for use by trained formulators.