Side-by-side · Research reference

AHK-CuvsDihexa

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-StrongHUMAN-REVIEWED7/28 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

Dihexa

Angiotensin IV Analogue · Pre-Clinical

Pre-clinicalDevelopment stage

Rodent onlyEvidence basisBenoist 2014

HGF/c-MetTarget systemWright 2015

Not established — animal studies only

01Mechanism of Action

Parameter

AHK-Cu

Dihexa

Primary target

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

c-Met receptor (HGF receptor tyrosine kinase)

Pathway

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

HGF/c-Met receptor activation → downstream signaling cascade → synaptogenesis and dendritic arborization

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

Induction of dendritic arborization, synapse formation, neurogenesis, and neuroprotection in rodent models

Feedback intact?

—

Origin

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

Small-molecule angiotensin IV analogue designed to activate HGF/c-Met systemWright 2015

Antibody development

—

02Dosage Protocols

Parameter

AHK-Cu

Dihexa

Effective concentration (in vitro)

10⁻¹² – 10⁻⁹ MPyo 2007

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

—

Topical formulation

0.001–0.01% (estimated cosmetic range)

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

—

Frequency

Once or twice daily (topical application)

—

Route

Topical — scalp or dermal application

—

Evidence basis

Ex vivo hair follicle / in vitro DPC studiesPyo 2007

Pre-clinical / Rodent models

Duration

Not established — cosmetic protocols typically 8–12 weeks

—

Human dosing

—

Not established — no human trials

Animal studies

—

Mouse/rat models only — dosing not translatable to humans

Clinical status

—

No Phase 1, 2, or 3 trials published

04Side Effects & Safety

Parameter

AHK-Cu

Dihexa

Local irritation

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

—

Copper sensitivity

Rare hypersensitivity reaction in copper-sensitive individuals

—

Systemic absorption

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

—

Data limitations

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

—

Human safety data

—

None available — no human clinical trials

Theoretical c-Met risks

—

c-Met receptor activation has been implicated in tumorigenesis; unknown cancer risk profile

Pre-clinical tolerability

—

Not systematically reported in available studies

Absolute Contraindications

AHK-Cu

·Known copper allergy or Wilson's disease

Dihexa

·Not approved for human use — research compound only

Relative Contraindications

AHK-Cu

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

Dihexa

·Theoretical contraindication: active or history of malignancy (c-Met pathway involvement in cancer)

05Administration Protocol

Parameter

AHK-Cu

Dihexa

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.

No established protocol. Dihexa has not been tested in human subjects. Animal studies used various routes (typically subcutaneous or intraperitoneal in rodents) not translatable to clinical use.

2. Frequency

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

Pre-clinical research compound. Not approved by FDA or any regulatory authority for human use.

3. Scalp preparation

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

—

4. Storage

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

—

5. Duration

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

—

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

Dihexa

— no documented stacks