Side-by-side · Research reference

HexarelinvsMatrixyl

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

APhase 1HUMAN-REVIEWED19/45 cited

BAnimal-MechanisticHUMAN-REVIEWED9/39 cited

Hexarelin

Hexapeptide GHRP · Cardio-tropic

100–200 mcgPer doseSmith 1996

Phase 1Evidence levelGhigo 1997

~70 minHalf-lifeSemenistaya 2010

SQ · Multiple sites · 1–3×/day

Matrixyl

Cosmeceutical Pentapeptide · Topical Anti-Aging

TopicalRoute

5-AALength (KTTKS)Gomes 2022

Collagen I/IIIPrimary targetPaccola 2025

Topical · Dermal · Twice Daily

01Mechanism of Action

Parameter

Hexarelin

Matrixyl

Primary target

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

Dermal fibroblastsPaccola 2025

Pathway

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

Fibroblast stimulation → Collagen I/III/IV synthesis → Glycosaminoglycan deposition → ECM remodeling

Downstream effect

Strong GH pulse + IGF-1 elevation; cardio-protective effects in animal MI modelsGhigo 1997

Enhanced extracellular matrix synthesis, improved dermal density, collagen remodelingPaccola 2025

Feedback intact?

Yes initially; tachyphylaxis with chronic useGhigo 1997

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Origin

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

Synthetic pentapeptide KTTKS derived from pro-collagen I fragment, N-palmitoylated for lipophilicityGomes 2022

Antibody development

—

02Dosage Protocols

Parameter

Hexarelin

Matrixyl

Standard dose

100–200 mcg per injectionSmith 1996

—

Frequency

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

—

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 1 / Phase 2 trialsSmith 1996 Ghigo 1997

—

Duration

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

8–12 weeks minimum for visible effect

Collagen synthesis requires sustained application.

Reconstitution

Bacteriostatic water

—

Timing

Pre-sleep + fasted preferred

—

Half-life

~70 minSemenistaya 2010

—

Formulation concentration

—

0.5–5% in topical vehicle

Common cosmeceutical range; higher concentrations in clinical formulations.

Application frequency

—

Twice daily (AM/PM)

Standard cosmeceutical protocol.

In vitro evidence

—

Fibroblast viability + ECM gene upregulationPaccola 2025

Vehicle

—

Serum, cream, or emulsion base

Lipophilic carriers enhance penetration.

04Side Effects & Safety

Parameter

Hexarelin

Matrixyl

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

—

Irritation

—

Mild erythema, pruritus in sensitive skin (rare)

Allergic reaction

—

Contact dermatitis (uncommon)

Systemic absorption

—

Negligible — topical application only

Absolute Contraindications

Hexarelin

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

Matrixyl

·Known hypersensitivity to palmitoyl peptides

Relative Contraindications

Hexarelin

·Untreated diabetes
·Severe hyperprolactinemia

Matrixyl

·Active dermatitis or open wounds at application site

05Administration Protocol

Parameter

Hexarelin

Matrixyl

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.

Wash face with gentle cleanser. Pat dry.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

Apply 2–3 drops to fingertips. Massage gently into target areas (face, neck, décolletage). Allow 1–2 minutes for absorption.

3. Timing

Pre-sleep + fasted preferred. Cycle on/off to avoid tachyphylaxis.

Twice daily — morning and evening. Apply before heavier creams or sunscreen.

4. Storage

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

Store at room temperature, away from direct sunlight. Stable in formulation for 12–24 months.

5. Needle

29–31G, 4–8 mm insulin syringe.

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06Stack Synergy

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

Matrixyl

+ GHK-Cu

Multi-pathway

View GHK-Cu →

Matrixyl (Pal-KTTKS) stimulates fibroblast collagen synthesis via pro-collagen I mimicry, while GHK-Cu acts as a copper-binding tripeptide that enhances ECM remodeling through metalloproteinase modulation and wound healing pathways. Combined, they address collagen synthesis (Matrixyl) and matrix remodeling/repair (GHK-Cu) through distinct mechanisms, producing complementary effects on dermal architecture.

Matrixyl: 0.5–5% topical serum · AM/PM
GHK-Cu: 1–2% topical serum · same application
Frequency: Twice daily
Primary benefit: Enhanced collagen synthesis + ECM remodeling, improved skin density and elasticity