Muscle & Growth Hormone
GHRP-2
Pralmorelin · KP-102
What it is
GHRP-2 is an older-generation six-amino-acid growth hormone-releasing peptide developed in the late 1990s. Used clinically as a diagnostic agent for GH deficiency in Japan (under the name Pralmorelin). Mostly superseded by Ipamorelin for off-label/biohacker use because of cleaner side-effect profile.
How it works
Activates ghrelin receptors in the pituitary to release GH. Stronger pulse than Ipamorelin but with modest cortisol and prolactin elevation as side effects.
Benefits
- Strong GH release
- Improved sleep
- Lean muscle gain over months
- Modest fat loss
- Cheaper than Ipamorelin
Timeline
- Week 1–2
- Improved sleep; appetite increase common.
- Week 4–6
- Body composition changes visible.
- Week 8–12
- Peak benefits; cycle off to reset.
Dosing & titration
Standard dose100–300 mcg, 1–3x daily
Cycle length8–12 weeks on, 4 weeks off
TimingEmpty stomach, paired with a GHRH (CJC, Mod GRF)
When to titrate upAbove 300 mcg per dose, cortisol/prolactin spike worsens. Most users prefer Ipamorelin's cleaner profile.
Side effects & risks
- Modest cortisol elevation
- Prolactin elevation (can cause emotional/sexual side effects)
- Hunger increase
- Tingling, head-rush after injection
Mostly outdated for daily use. Ipamorelin produces similar GH release without cortisol/prolactin issues.
Typical price
$50–$80/mo5 mg vial from a 503A compounding pharmacy.
Studies
- Search PubMed for GHRP-2 — PubMed searchLive PubMed search
- Bowers CY et al. The first GH-releasing peptide trials — Foundational work by the discoverer of the GHRP class. PubMedJCEM, 1994
Educational reference only. Not medical advice.