Side-by-side · Research reference

AHK-CuvsCortagen

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

AAnimal-MechanisticHUMAN-REVIEWED14/43 cited

BAnimal-MechanisticHUMAN-REVIEWED11/35 cited

AHK-Cu

Tripeptide-Copper Complex · Cosmetic

10⁻¹² – 10⁻⁹ MActive range (in vitro)Pyo 2007

Dermal papilla cellsPrimary targetPyo 2007

TopicalRoute

Topical · Scalp / Skin

Cortagen

Bioregulatory Tetrapeptide · Khavinson-School

TetrapeptideStructure

↓ LPO productsAntioxidant effectKozina 2007

AnimalEvidence level

Injectable · Animal models

01Mechanism of Action

Parameter

AHK-Cu

Cortagen

Primary target

Dermal papilla cells (DPCs) — specialized fibroblasts in hair follicle morphogenesisPyo 2007

Cerebral cortex tissue — molecular targets under investigation

Pathway

AHK-Cu → DPC proliferation → VEGF elevation, TGF-β1 suppression → Angiogenesis, follicle elongationPyo 2007

Antioxidant pathway modulation — suppression of LPO cascade, reduction of protein oxidative modificationKozina 2007

Downstream effect

Stimulates hair follicle elongation ex vivo, reduces dermal papilla cell apoptosis, elevates Bcl-2/Bax ratio, reduces cleaved caspase-3 and PARPPyo 2007

Decreased lipid peroxidation products, reduced oxidative protein damage, altered gene expression in cardiac tissueKozina 2007 Anisimov 2004

Feedback intact?

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Origin

Synthetic tripeptide with Cu²⁺ chelation — alanine substitution variant of GHK-Cu

Synthetic tetrapeptide derived from amino acid analysis of natural brain cortex peptide preparation CortexinAnisimov 2004

Antibody development

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02Dosage Protocols

Parameter

AHK-Cu

Cortagen

Effective concentration (in vitro)

10⁻¹² – 10⁻⁹ MPyo 2007

Stimulated human hair follicle elongation ex vivo and DPC proliferation in vitro.

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Topical formulation

0.001–0.01% (estimated cosmetic range)

No standardized human protocol published — extrapolated from in vitro data.

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Frequency

Once or twice daily (topical application)

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Route

Topical — scalp or dermal application

Injectable (inferred from animal protocols)

Evidence basis

Ex vivo hair follicle / in vitro DPC studiesPyo 2007

Animal mechanistic studies

Duration

Not established — cosmetic protocols typically 8–12 weeks

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Animal model dose (rat)

—

Injection protocol (dose not specified in abstracts)

Multiple injections over study period.

Avian model dose (chicken)

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40-day injection courseKuznik 2008

Compared to epithalon in hypophysectomized and aged birds.

Human peripheral nerve study

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Therapeutic course (protocol details not provided)

Posttraumatic recovery context — reference cited but not detailed.

04Side Effects & Safety

Parameter

AHK-Cu

Cortagen

Local irritation

Mild erythema, pruritus at application site (copper peptide class effect)

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Copper sensitivity

Rare hypersensitivity reaction in copper-sensitive individuals

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Systemic absorption

Minimal via topical route — systemic copper toxicity unlikely at cosmetic doses

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Data limitations

No published human safety trials — cosmetic use presumed safe per class precedent (GHK-Cu)

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Antioxidant suppression

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Suppression of antioxidant activity noted alongside LPO reductionKozina 2007

Mechanism unclear — possible homeostatic adaptation.

Immune/hemostasis effects

—

No effect on immunity or hemostasis parameters in avian hypophysectomy model (unlike epithalon)Kuznik 2008

Epithalon reversed deficits; cortagen did not.

Human safety data

—

No adverse events reported in peripheral nerve recovery context

Limited detail in available abstracts.

Absolute Contraindications

AHK-Cu

·Known copper allergy or Wilson's disease

Cortagen

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Relative Contraindications

AHK-Cu

·Broken or inflamed skin (increased absorption risk)
·Concurrent use of other copper-containing formulations

Cortagen

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05Administration Protocol

Parameter

AHK-Cu

Cortagen

1. Topical application

Apply to clean, dry scalp or target dermal area. Typical cosmetic formulations: 0.001–0.01% AHK-Cu in serum or cream base.

Reconstitute lyophilised peptide with bacteriostatic water per supplier protocol. Exact volumes depend on concentration supplied.

2. Frequency

Once or twice daily. Evening application preferred for overnight contact time.

Subcutaneous injection typical for bioregulatory peptides — abdomen or thigh. Rotate sites.

3. Scalp preparation

For hair growth: apply directly to scalp, massage gently. No need to rinse. Allow absorption for minimum 2–4 hours.

Animal protocols used repeated dosing over weeks. Human timing not established — evening administration common in Khavinson tradition.

4. Storage

Room temperature, protected from light. Copper complexes may degrade in UV exposure.

Lyophilised: refrigerate or freeze per supplier. Reconstituted: refrigerate 2–8 °C, use within guideline window.

5. Duration

Minimum 8–12 weeks to assess efficacy in hair growth applications, per typical cosmetic peptide protocols.

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06Stack Synergy

AHK-Cu

+ GHK-Cu

Moderate

View GHK-Cu →

Both tripeptide-copper complexes share overlapping angiogenic and wound-healing mechanisms (VEGF elevation, TGF-β modulation, fibroblast proliferation). AHK-Cu's alanine substitution may offer distinct receptor affinity or pharmacokinetics. Co-formulation could provide complementary dermal signaling, though no direct synergy studies exist. Often used interchangeably or in alternating protocols.

AHK-Cu: 0.001–0.01% topical · AM
GHK-Cu: 0.001–0.01% topical · PM
Frequency: Daily alternation or combined formulation
Primary benefit: Comprehensive dermal regeneration, angiogenesis, hair follicle support

Cortagen

— no documented stacks