Side-by-side · Research reference

AHK-CuvsGHRP-2

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 2HUMAN-REVIEWED15/42 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

GHRP-2

Hexapeptide GHRP · Phase 2 (clinical diagnostic)

100–300 mcgPer doseBowers 1990

Phase 2Evidence levelBowers 1990 Sigalos 2018

~30 minHalf-lifeMalagón 1999

SQ · Multiple sites · 1–3×/day

01Mechanism of Action

Parameter

AHK-Cu

GHRP-2

Primary target

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

Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990

Pathway

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

GHS-R1a → Gαq → Ca²⁺ → GH vesicle exocytosisBowers 2002

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

Strong GH pulse + IGF-1 elevation; appetite increase via ghrelin agonismBowers 2002

Feedback intact?

—

Yes, with somatostatin feedback active

Origin

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

Synthetic hexapeptide; developed by Bowers/Tulane group in the 1980sBowers 1990

Antibody development

—

02Dosage Protocols

Parameter

AHK-Cu

GHRP-2

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)

1–3× per day

Route

Topical — scalp or dermal application

—

Evidence basis

Ex vivo hair follicle / in vitro DPC studiesPyo 2007

Phase 2 + clinical diagnostic useBowers 1990

Duration

Not established — cosmetic protocols typically 8–12 weeks

8–12 weeks on / 4 off (anecdotal)

Standard dose

—

100–300 mcg per injectionBowers 1990

Lower / starter dose

—

50 mcg per dose

Reconstitution

—

Bacteriostatic water

Timing

—

Pre-sleep + fasted preferred

Half-life

—

~30 minMalagón 1999

04Side Effects & Safety

Parameter

AHK-Cu

GHRP-2

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)

—

Cortisol elevation

—

Mild but measurableBowers 1990

Prolactin elevation

—

Mild but measurable

Hunger

—

Strong appetite increase

Injection site reaction

—

Mild erythema

IGF-1 elevation

—

Strong; monitor with chronic high-dose use

Cancer risk

—

Contraindicated in active malignancy

Pregnancy / OB

—

Avoid

Absolute Contraindications

AHK-Cu

·Known copper allergy or Wilson's disease

GHRP-2

·Active malignancy
·Pregnancy / breastfeeding

Relative Contraindications

AHK-Cu

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

GHRP-2

·Untreated diabetes

05Administration Protocol

Parameter

AHK-Cu

GHRP-2

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 5 mg vial → 2.5 mg/mL.

2. Frequency

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

SQ — 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.

Pre-sleep + fasted preferred.

4. Storage

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

Lyophilised: room temp, 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, 4–8 mm 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

GHRP-2

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

GHRP-2 + CJC-1295-no-DAC is a higher-amplitude alternative to the ipamorelin + CJC-1295 stack. GHRP-2 produces a stronger pulse but with cortisol + prolactin signal — choose when maximum GH amplitude is the goal and the side-effect tolerance is acceptable.

GHRP-2: 100–200 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: High-amplitude GH pulse, body composition

Bowers 1990 Teichman 2006