GHRP-2

GHRP-2 (Inj)

GHRP-2 (Growth Hormone Releasing Peptide-2) is a synthetic hexapeptide that stimulates growth hormone (GH) release by binding to the ghrelin receptor (GHS-R1a) in the pituitary and hypothalamus. It is one of the most potent GH-releasing peptides available, producing strong GH pulses when administered. GHRP-2 is commonly used in research for GH deficiency evaluation, muscle gain, fat loss, recovery, and anti-aging protocols, often combined with a GHRH analog like CJC No DAC.

Dosing Protocols

— 5 mg Vial —

Reconstitute: Add 3.0 mL bacteriostatic water → ~1.67 mg/mL concentration.
Typical daily range: 100–300 mcg once daily subcutaneously.
Easy measuring: At 1.67 mg/mL, 1 unit = 0.01 mL ≈ 16.7 mcg on a U-100 insulin syringe.
Storage: Lyophilized: freeze at −20 °C; reconstituted: refrigerate at 2–8 °C.

Schedule: Daily subcutaneous injections for 8–12 weeks.
Cycle Length: 8–16 weeks.
Goal: Stimulate endogenous growth hormone secretion through ghrelin receptor activation.

Frequency: Inject once daily subcutaneously. Administering in the evening may capitalize on nocturnal GH rhythms.

Phase	Dose	Syringe (U-100)
Weeks 1–2	100 mcg	6 units (0.06 mL)
Weeks 3–4	150 mcg	9 units (0.09 mL)
Weeks 5–8	200 mcg	12 units (0.12 mL)
Weeks 9–16	200–300 mcg	12–18 units (0.12–0.18 mL)

— 10 mg Vial —

Reconstitute: Add 3.0 mL bacteriostatic water → ~3.33 mg/mL concentration.
Typical daily range: 100–300 mcg once daily (gradual titration).
Easy measuring: At 3.33 mg/mL, 1 unit ≈ 33.3 mcg on a U-100 insulin syringe.
Storage: Lyophilized: freeze at −20 °C; reconstituted: refrigerate at 2–8 °C, avoid freeze-thaw cycles.

Schedule: Daily subcutaneous injections for 8–12 weeks.
Cycle Length: 8–12 weeks; optional extension to 16 weeks with periodic breaks.
Goal: Stimulate pulsatile growth hormone release and elevate IGF-1 levels over time.

Frequency: Inject once daily subcutaneously, typically before sleep to coincide with natural GH pulsatility.

Phase	Dose	Syringe (U-100)
Weeks 1–2	100 mcg	3 units (0.03 mL)
Weeks 3–4	150 mcg	4.5 units (0.045 mL)
Weeks 5–8	200 mcg	6 units (0.06 mL)
Weeks 9–12	250–300 mcg	7.5–9 units (0.075–0.09 mL)

Benefits

• Strong, dose-dependent GH release (among strongest of the GHRPs)
• Increases IGF-1 levels downstream of GH elevation
• Promotes lean muscle mass and strength
• Accelerates fat oxidation and body composition improvements
• Improves sleep quality (deep sleep enhancement)
• Enhances recovery from exercise and injury
• Cardioprotective effects — reduces cardiac ischemia markers
• Anti-inflammatory properties
• Stimulates appetite (via ghrelin receptor activation)
• Increases cortisol and prolactin (minor, dose-dependent)

Mechanism of Action

GHRP-2 acts as a synthetic ghrelin mimetic, binding to GHS-R1a (the ghrelin receptor) in pituitary somatotroph cells and hypothalamic neurons. This binding directly stimulates GH secretion from the pituitary while also amplifying GHRH signaling and suppressing somatostatin (the GH inhibitor). GHRP-2 produces robust GH pulses within 15–30 minutes of injection. When combined with a GHRH analog (e.g., CJC No DAC), the synergistic effect produces GH release several times greater than either peptide alone.

Side Effects

• Increased appetite — significant ghrelin receptor effect
• Elevated cortisol and prolactin (at higher doses)
• Water retention
• Tingling or numbness (carpal tunnel-like at high doses)
• Fatigue immediately post-injection in some users
• Potential for desensitization with continuous use

Side Effect Management

Cycle GHRP-2 rather than using continuously to prevent receptor desensitization (5 days on / 2 days off, or monthly breaks). Control appetite effects by timing injections away from meals (fasted state maximizes GH release). Monitor cortisol and prolactin if using at high doses long-term. Combine with a GHRH peptide for maximum GH pulse.

Contraindications

• Active malignancy or cancer history (GH/IGF-1 may promote tumor growth)
• Diabetic retinopathy
• Acromegaly or GH-secreting tumors
• Pregnancy and lactation
• Severe carpal tunnel syndrome

Research Citations

• Bowers CY et al. (1996). Growth hormone-releasing peptide-2. Journal of Clinical Endocrinology & Metabolism. DOI: 10.1210/jc.81.3.1191
• Arvat E et al. (1997). Effects of GHRP-2 and GHRP-6 on GH secretion in humans. Journal of Clinical Investigation. DOI: 10.1172/JCI119559
• Ghigo E et al. (2007). Growth hormone secretagogues: potential clinical relevance. Pituitary. DOI: 10.1007/s11102-007-0049-3

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