Clinical Pharmacology & Mechanism of Action
GHRP-2 (also known as Pralmorelin) is a synthetic hexapeptide and a potent, first-generation Growth Hormone Releasing Peptide. It operates as a powerful agonist of the ghrelin/growth hormone secretagogue receptor (GHSR).
While GHRHs (like CJC-1295) stimulate the pituitary to produce growth hormone, GHRPs like GHRP-2 stimulate the pituitary to release stored growth hormone while simultaneously suppressing somatostatin (the body's natural GH inhibitor) .
GHRP-2 is widely considered to sit in the "middle ground" of the GHRP family:
- It is significantly more potent at releasing GH than Ipamorelin.
- It does not cause the severe, uncontrollable gastric hunger associated with GHRP-6.
- However, it does mildly elevate levels of cortisol (the stress hormone) and prolactin, which makes it less "clean" than Ipamorelin but much stronger milligram-for-milligram.
Pharmacokinetics & Timing
- Half-life: Very short (approximately 15 to 30 minutes).
- Pulse Duration: It induces a massive spike in serum GH levels that peaks within 30-45 minutes and returns to baseline within 2 to 3 hours.
Because it clears the system so quickly, it relies entirely on inducing a rapid pulse. If the injection is timed poorly (e.g., when insulin is high), the pulse will be destroyed and the dose wasted.
Standard Research Dosing Protocols
Like all GHRPs, GHRP-2 is almost exclusively stacked with a GHRH (like CJC-1295 No DAC) to achieve a synergistic GH pulse.
- Dosage: 100mcg to 150mcg per injection.
- Saturation Point: GHRP-2 saturates the pituitary receptors quickly. Injecting more than 200mcg yields rapidly diminishing returns. The pituitary physically cannot dump more GH than it has stored.
- Frequency: 1 to 3 times daily (morning, post-workout, before bed).
- Fasting Requirement: Must be injected on a strictly empty stomach (2 hours post-meal, wait 30 mins before eating again).
Reconstitution Math & Syringe Guide
GHRP-2 is highly potent and typically sold in 5mg vials. Because doses are exceptionally small (100mcg), reconstitution math is critical to avoid drawing microscopic, inaccurate amounts of liquid.
Step-by-Step Reconstitution (5mg Vial)
- Swab the rubber stoppers of your 5mg GHRP-2 vial and Bacteriostatic Water.
- Using a sterile mixing syringe, draw exactly 2mL of Bacteriostatic Water.
- Inject the water slowly down the inside wall of the GHRP-2 vial.
- Swirl gently.
The Math for a Standard Dose (100mcg):
- 5mg total in the vial = 5,000mcg.
- You added 2mL of water.
- Therefore, the concentration is 2,500mcg per 1mL.
- You need a 100mcg dose. Divide the dose by the concentration: 100 ÷ 2,500 = 0.04mL.
- 0.04mL = 4 units on a U-100 syringe.
(If drawing exactly 4 units is too difficult with your syringes, you can add 4mL of water instead. This changes the concentration to 1,250mcg/mL, making a 100mcg dose equal to 8 units).
Common Mistakes & Troubleshooting
- Drawing Too Much Liquid: Because 4 units is barely a drop in a standard insulin syringe, many researchers mistakenly draw 40 units, effectively injecting 1,000mcg. This massive overdose will cause severe flushing, lethargy, and spikes in prolactin/cortisol.
- Ignoring Prolactin: For researchers sensitive to prolactin (which can cause water retention and gynecomastia in males), running GHRP-2 at high doses multiple times a day can trigger issues. Ipamorelin is usually preferred for sensitive individuals.
- Eating Carbs Too Soon: Consuming carbohydrates causes an insulin spike. Insulin directly blunts the GH release triggered by GHRP-2.