Side-by-side · Research reference

AHK-CuvsHexarelin

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-REVIEWED19/45 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

Hexarelin

Hexapeptide GHRP · Cardio-tropic

100–200 mcgPer doseSmith 1996

Phase 1Evidence levelGhigo 1997

~70 minHalf-lifeSemenistaya 2010

SQ · Multiple sites · 1–3×/day

01Mechanism of Action

Parameter

AHK-Cu

Hexarelin

Primary target

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

Ghrelin receptor (GHS-R1a) + cardiac CD36Smith 1996 Ghigo 1997

Pathway

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

GHS-R1a → Gαq → Ca²⁺ → GH release. CD36 engagement → direct cardio-tropic actionGhigo 1997

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; cardio-protective effects in animal MI modelsGhigo 1997

Feedback intact?

—

Yes initially; tachyphylaxis with chronic useGhigo 1997

Origin

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

Synthetic hexapeptide His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂Smith 1996

Antibody development

—

02Dosage Protocols

Parameter

AHK-Cu

Hexarelin

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)

1–2× per day max (tachyphylaxis with chronic 3× daily)

Route

Topical — scalp or dermal application

—

Evidence basis

Ex vivo hair follicle / in vitro DPC studiesPyo 2007

Phase 1 / Phase 2 trialsSmith 1996 Ghigo 1997

Duration

Not established — cosmetic protocols typically 8–12 weeks

4–8 weeks on / 4–8 weeks off (tachyphylaxis mitigation)

Standard dose

—

100–200 mcg per injectionSmith 1996

Lower / starter dose

—

50 mcg per dose

Reconstitution

—

Bacteriostatic water

Timing

—

Pre-sleep + fasted preferred

Half-life

—

~70 minSemenistaya 2010

04Side Effects & Safety

Parameter

AHK-Cu

Hexarelin

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

—

Modest at high dosesGhigo 1997

Prolactin elevation

—

Modest at high dosesGhigo 1997

Hunger

—

Strong appetite increase via ghrelin agonism

Tachyphylaxis

—

Receptor desensitisation with chronic dosingGhigo 1997

Cardiac effects

—

Direct cardio-tropic; potential benefit in MI but unstudied in humansGhigo 1997

IGF-1 elevation

—

Strong; monitor with chronic high-dose use

Cancer risk

—

Contraindicated in active malignancy (GH/IGF-1 axis)

Pregnancy / OB

—

Avoid

Absolute Contraindications

AHK-Cu

·Known copper allergy or Wilson's disease

Hexarelin

·Active malignancy
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Relative Contraindications

AHK-Cu

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

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

05Administration Protocol

Parameter

AHK-Cu

Hexarelin

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 = 250 mcg per 0.1 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. Cycle on/off to avoid tachyphylaxis.

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

Hexarelin

+ CJC-1295 (no DAC)

Strong

View CJC-1295 (no DAC) →

Hexarelin (GHRP) + CJC-1295-no-DAC (GHRH analogue) is the higher-amplitude variant of the standard GHRH+GHRP stack. Hexarelin produces a stronger pulse than ipamorelin but with cortisol + prolactin signal — choose this stack for maximum GH amplitude when side-effect tolerance is acceptable. Cycle aggressively.

Hexarelin: 100 mcg SQ · pre-sleep
CJC-1295 (no DAC): 100 mcg SQ · same injection
Primary benefit: Maximum GH pulse amplitude (with side-effect signal)

Smith 1996 Teichman 2006