GHRP-2

GHRP-2 is a synthetic hexapeptide that binds the growth hormone secretagogue receptor (GHSR-1a) — the same receptor as MK-677 and ipamorelin — to trigger GH release. The difference is selectivity, or rather the lack of it: alongside GH, GHRP-2 measurably raises cortisol and prolactin, both off-target. It also stokes appetite, though less than ghrelin itself does. What sets it apart is regulatory rather than pharmacological — Japan approves and markets it as pralmorelin for diagnostic testing of pituitary GH reserve, a clinical footprint most research-compound GHRPs never earn. It needs an intact pituitary and working hypothalamic GHRH tone to do its best work, and it synergizes with GHRH given alongside it.

GHRP-2 carries more clinical data than ipamorelin or CJC-1295 — but read where that data comes from. Most of it rides on its Japanese approval as a diagnostic agent for pituitary GH reserve, a setting where it reliably and reproducibly provokes GH across age groups. Teramoto et al. (2023, Growth Hormone & IGF Research) used the GHRP-2 stimulation test in elderly patients and confirmed robust GH responses. A broader review by Sigalos and Pastuszak (2018, Sexual Medicine Reviews) covers GHRP-2 among the GH secretagogues, crediting the GH-stimulating effect while flagging the cortisol and prolactin co-secretion. Notice what is not on that list: the uses people actually buy it for. Body composition, recovery, anti-aging — in the US it is a research compound with no approved indication, and no therapeutic RCT in those populations exists.

• Reliable pituitary GH stimulation in humans — the basis for its diagnostic use in Japan
• Robust GH responses in elderly patients in the GHRP-2 stimulation test (Teramoto 2023)
• Stronger GH stimulation when combined with GHRH in human studies
• A more established human pharmacodynamic profile than most other research-compound GHRPs

• Elevates cortisol and prolactin alongside GH — less selective than ipamorelin
• No approved therapeutic indication in the US; sold for research use only
• Appetite stimulation possible via ghrelin receptor pathway
• Diagnostic-use approval in Japan does not imply safety or efficacy for the therapeutic uses sought by consumers
• Injection required; purity of research-grade supplies is supplier-dependent
• Banned in sport by WADA

Research compound. Sold "for research use only" — not approved for human consumption.

Goals studied: GH / IGF-1 support

Is GHRP-2 approved anywhere?

Yes — in Japan, it is approved as pralmorelin for diagnostic testing of pituitary GH secretory reserve. In the US and most other countries, it has no approved indication and is sold as a research compound only.

How does GHRP-2 compare to ipamorelin?

Both activate the GHSR (ghrelin receptor) to stimulate GH. Ipamorelin was specifically developed to be receptor-selective, avoiding the cortisol and prolactin elevation seen with GHRP-2. GHRP-2, however, has more published human data. Neither has therapeutic RCTs for the uses biohackers seek.

Is GHRP-6 similar?

Yes, GHRP-6 is the parent compound in the same hexapeptide GHRP family. GHRP-2 generally produces stronger GH stimulation with a comparable side-effect profile. Both stimulate appetite and cortisol — GHRP-6 is historically known for causing pronounced hunger.

1. [1]
   The Safety and Efficacy of Growth Hormone Secretagogues

   Sigalos JT, Pastuszak AW · Sexual Medicine Reviews · 2018 · PMID 28400207 · model: human

   Clinical review of GH secretagogues (including GHRP-2) covering mechanism, human efficacy data, and safety considerations including the cortisol and prolactin co-secretion characteristic of GHRP-2.

2. [2]
   Assessment of anterior pituitary reserve capacity based on growth hormone response to growth hormone-releasing peptide-2 test in the elderly

   Teramoto S, Tahara S, Hattori Y, Kondo A, Morita A · Growth Hormone & IGF Research · 2023 · PMID 37295337 · model: human

   Prospective use of the GHRP-2 stimulation test in elderly patients demonstrating robust and measurable GH responses, supporting GHRP-2's utility as a human pituitary reserve assessment tool.