Growth Hormone
CAS
158861-67-7
Molecular Weight
818
Da
GHRP-2 (Growth Hormone Releasing Peptide-2) is a synthetic hexapeptide that stimulates the pituitary gland to release growth hormone. It is one of the most studied compounds in the GHRP class, with a meaningful human pharmacological evidence base spanning the 1990s through 2010s. However, evidence is concentrated in pharmacokinetic and short-term endocrine studies rather than long-term therapeutic trials. It scores higher than related compounds Ipamorelin and Hexarelin due to greater independent replication, but has never advanced to Phase III trials.
Injectable
Intranasal Suitable
Uncertain
Research Compound
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GHRP-2 has a long history in the peptide research community, predating most current GHRPs by over a decade. It is generally viewed as a second-generation GHRP with a meaningful pharmacological evidence base but unfavorable side-effect profile compared to Ipamorelin, specifically the cortisol and prolactin elevation. Most experienced community members who discuss GHRP-2 note they prefer Ipamorelin for ongoing use while acknowledging GHRP-2's GH pulse amplitude is stronger per dose. Often stacked with CJC-1295. Discussion has declined in recent years as Ipamorelin became the dominant GHRP option.
GHRP-2 (pralmorelin) is a synthetic peptide that acts as a ghrelin mimetic and potent secretagogue of growth hormone. It was developed in the 1990s alongside GHRP-6 as part of a broader effort to find small-molecule alternatives to GH therapy. GHRP-2 is notable for being approved in Japan (as Macimorelin's predecessor class) for GH deficiency diagnosis and for its relatively robust pharmacokinetic literature compared to other GHRPs.
GHRP-2 binds the growth hormone secretagogue receptor (GHSR-1a), the same receptor as ghrelin, in the hypothalamus and pituitary. This triggers a pulsatile release of growth hormone, distinct from the sustained elevation that exogenous GH produces. GHRP-2 also has mild appetite-stimulating effects via central ghrelin receptor activation, though weaker than GHRP-6. It may potentiate the effect of GHRH analogs (such as CJC-1295 or Sermorelin) when co-administered, as the two pathways converge on GH secretion through different mechanisms.
In clinical research, GHRP-2 has been used as a diagnostic tool for GH deficiency evaluation and studied for its effects on GH secretion, body composition, and muscle anabolism. In the research/biohacking community, it is used for similar purposes to Ipamorelin and Sermorelin, GH pulse stimulation, recovery, body composition, often combined with a GHRH analog. Evidence supports GH secretion in humans; evidence for downstream therapeutic outcomes (muscle gain, fat loss, recovery) in healthy adults is limited to small observational studies.
GHRP-2 stimulates cortisol and prolactin release in addition to GH, a distinguishing risk profile from Ipamorelin, which is more GH-selective. Elevated cortisol and prolactin with chronic use is a theoretical concern not fully characterized in long-term studies. Injection site reactions, water retention, and appetite stimulation (hunger) are commonly reported. As with all GH-axis compounds, long-term safety in healthy adults is unstudied.
GHRP-2 is available as a lyophilized powder for reconstitution and injection in research chemical contexts. It is not commercially approved for therapeutic use in the US or EU. Subcutaneous administration is the standard research route. Nasal administration has been explored in animal models but lacks published human pharmacokinetic data (IN Suitability marked Uncertain). Purity varies between research chemical suppliers; third-party testing is advisable.
GHRP-2 is not approved by the FDA for any therapeutic indication. It has been used as a diagnostic agent in Japan (pralmorelin, Ghreplus) for GH deficiency provocative testing, though this is a distinct approved application from therapeutic use. In the US, it is classified as a research chemical and cannot be prescribed or dispensed. It was considered under FDA 503A compounding pharmacy bulk drug substance lists but does not appear on the approved list. Classified as doping in sport by WADA.
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