Side-by-side · Research reference

CJC-1295 (no DAC)vsMatrixyl

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

APhase 1HUMAN-REVIEWED15/51 cited

BAnimal-MechanisticHUMAN-REVIEWED9/39 cited

CJC-1295 (no DAC)

Short-acting GHRH · No DAC variant

100 mcgPer doseTeichman 2006

~30 minHalf-lifeIonescu 2006

Phase 1Evidence levelTeichman 2006 Sigalos 2018

SQ · Pre-sleep · 1–2×/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

CJC-1295 (no DAC)

Matrixyl

Primary target

Pituitary GHRH receptorTeichman 2006

Dermal fibroblastsPaccola 2025

Pathway

GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisTeichman 2006

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

Downstream effect

Pulsatile GH release matching physiological pattern; subsequent IGF-1 elevationIonescu 2006

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

Feedback intact?

Yes — short pulse preserves somatostatin negative feedbackIonescu 2006

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Origin

Modified human GRF 1-29 with four substitutions (D-Ala²/Gln⁸/Ala¹⁵/Leu²⁷) for protease resistanceTeichman 2006

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

Antibody development

Not reported in short-term studies

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02Dosage Protocols

Parameter

CJC-1295 (no DAC)

Matrixyl

Standard dose

100 mcg per injectionTeichman 2006

Often paired with ipamorelin in same syringe.

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Frequency

1–2× daily (pre-sleep ± morning)

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Lower / starter dose

50 mcg per dose

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Evidence basis

Phase 1 (CJC-1295 with DAC); analog dataTeichman 2006 Ionescu 2006

No-DAC variant is less studied directly; PK extrapolated from native GHRH.

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Duration

8–12 weeks on / 4 off (anecdotal)

8–12 weeks minimum for visible effect

Collagen synthesis requires sustained application.

Reconstitution

Bacteriostatic water

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Timing

Pre-sleep + fasted preferred

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Half-life

~30 minIonescu 2006

Short pulse vs CJC-1295-DAC (~8 days). Choose no-DAC for pulsatile, DAC for sustained.

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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

CJC-1295 (no DAC)

Matrixyl

Injection site reaction

Erythema, mild pruritus

—

Flushing / headache

Common transient effect

—

Cortisol elevation

Minimal at standard doses

—

Prolactin elevation

Minimal

—

Glucose intolerance

Possible at high cumulative doses

—

IGF-1 elevation

Dose-dependent; monitor with chronic use

—

Cancer risk

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

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Pregnancy / OB

Avoid

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Irritation

—

Mild erythema, pruritus in sensitive skin (rare)

Allergic reaction

—

Contact dermatitis (uncommon)

Systemic absorption

—

Negligible — topical application only

Absolute Contraindications

CJC-1295 (no DAC)

·Active malignancy or cancer history
·Pregnancy / breastfeeding
·Disrupted hypothalamic-pituitary axis

Matrixyl

·Known hypersensitivity to palmitoyl peptides

Relative Contraindications

CJC-1295 (no DAC)

·Untreated diabetes
·Severe insulin resistance

Matrixyl

·Active dermatitis or open wounds at application site

05Administration Protocol

Parameter

CJC-1295 (no DAC)

Matrixyl

1. Reconstitution

Add 2 mL bacteriostatic water to 2 mg vial → 1 mg/mL = 100 mcg per 0.1 mL. Roll gently.

Wash face with gentle cleanser. Pat dry.

2. Injection site

Subcutaneous, 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 preferred. Often combined with ipamorelin in the same syringe.

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

4. Storage

Lyophilised: room temp, protected from light. Reconstituted: refrigerate 2–8 °C, use within 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

CJC-1295 (no DAC)

+ Ipamorelin

Strong

View Ipamorelin →

CJC-1295 (no DAC) and ipamorelin are the canonical "GHRH + GHRP" dual-axis stack at physiological timing. Both peak within 30 min and clear within 2 hours, producing a sharp, high-amplitude GH pulse closely resembling natural physiology. Preferred over the CJC-1295-DAC + ipamorelin stack when pulsatility (vs sustained elevation) is the goal.

CJC-1295 (no DAC): 100 mcg SQ · pre-sleep
Ipamorelin: 200–300 mcg SQ · same injection
Primary benefit: Pulsatile GH stimulation, recovery, body composition

Teichman 2006 Raun 1998

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