Side-by-side · Research reference

AHK-CuvsMelanotan-II

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

BPhase 1HUMAN-REVIEWED9/43 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

Melanotan-II

MC1R + MC4R agonist · Tanning + sexual response

0.25–1.0 mgPer doseDorr 1996

Phase 1Evidence levelDorr 1996

~1 hrHalf-life

SQ · Abdomen · Loading 5–7 days, then maintenance

01Mechanism of Action

Parameter

AHK-Cu

Melanotan-II

Primary target

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

MC1R (skin) + MC3R + MC4R (CNS sexual / appetite)Dorr 1996

Pathway

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

MC1R agonism → melanocyte tyrosinase → eumelanin synthesis. MC4R → autonomic sexual arousal centresDorr 1996 Simerly 2023

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

Skin darkening, photo-protection, increased sexual desire / spontaneous erectionDorr 1996

Feedback intact?

—

Origin

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

Cyclic 7-AA modified α-MSH analog; designed at University of ArizonaDorr 1996

Antibody development

—

02Dosage Protocols

Parameter

AHK-Cu

Melanotan-II

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)

Daily during loading; 1–2× per week maintenance

Route

Topical — scalp or dermal application

—

Evidence basis

Ex vivo hair follicle / in vitro DPC studiesPyo 2007

Phase 1 + anecdotalDorr 1996

Duration

Not established — cosmetic protocols typically 8–12 weeks

8–12 weeks per cycle

Loading phase

—

0.25–0.5 mg/day SQ × 5–7 daysDorr 1996

Builds up to visible tan.

Maintenance

—

0.5–1.0 mg 1–2×/week

After visible tan develops; supports with UV exposure.

Lower / starter dose

—

0.1 mg / day

Conservative starter — assess tolerability for nausea.

Reconstitution

—

Bacteriostatic water; protect from light

Timing

—

Evening preferred (24h tan-development cycle)

Half-life

—

~1 hour plasma; effects on melanocytes persist days

04Side Effects & Safety

Parameter

AHK-Cu

Melanotan-II

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)

—

Nausea

—

Common, especially loading phase

Flushing

—

Common transient

Spontaneous erection

—

Common in men — MC4R cross-effectDorr 1996

Increased mole / freckle pigmentation

—

Existing moles darken; new lesions possible

Melanoma risk

—

Theoretical concern — increased melanocyte activity; CAUTION in melanoma history

Appetite suppression

—

MC4R-mediated; mild

Pregnancy / OB

—

Contraindicated

Absolute Contraindications

AHK-Cu

·Known copper allergy or Wilson's disease

Melanotan-II

·History of melanoma or atypical mole syndrome
·Pregnancy / breastfeeding
·Active uncontrolled hypertension

Relative Contraindications

AHK-Cu

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

Melanotan-II

·Significant freckling / dysplastic nevus
·Personal or family melanoma history

05Administration Protocol

Parameter

AHK-Cu

Melanotan-II

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.

Add 2 mL bacteriostatic water to 10 mg vial → 5 mg/mL = 500 mcg per 0.1 mL. Light-protected.

2. Frequency

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

SQ — abdomen. 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.

Evening preferred. UV exposure (sunlight or tanning bed) helps develop tan.

4. Storage

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

Lyophilised: refrigerate, light-protected. Reconstituted: refrigerate ≤30 days.

5. Duration

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

29–31G insulin syringe.

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

Melanotan-II

— no documented stacks