GHRP-2 (Pralmorelin): Evidence, Mechanism & Legal Status

GHRP-2 (pralmorelin; developmental codes KP-102, GPA-748, WAY-GPA-748) is a synthetic hexapeptide and the first growth hormone secretagogue to reach clinical use. It is marketed in Japan as a single-dose diagnostic for growth hormone deficiency, yet it is sold worldwide on the gray market for GH 'optimization' and recovery — uses the evidence does not support.5 This monograph separates the validated diagnostic peptide from the hyped one.

This article is informational and editorial content for research and educational purposes only. It is not medical advice, not a protocol to follow, and not a sourcing or buying guide. GHRP-2 is not an FDA-approved drug; the only marketed product anywhere is a single-dose diagnostic in Japan. Dosing figures are reported strictly as they appear in the published literature and approved diagnostic labeling, for completeness — not as recommendations. Athletes: GHRP-2 is banned at all times under the WADA Code. Consult a licensed clinician before any health decision.

What is GHRP-2 and how does it work?

GHRP-2 is a synthetic hexapeptide, molecular formula C₄₅H₅₅N₉O₆ (MW ~818 g/mol, PubChem CID 6918245), with the sequence D-Ala–D-(β-naphthyl)-Ala–Ala–Trp–D-Phe–Lys-NH₂.4 It carries the international nonproprietary name pralmorelin and is a non-natural 'super-analogue' of GHRP-6.3 Full chemistry and registry data are public on PubChem (CID 6918245).4

The mechanism is well characterized. GHRP-2 is an agonist of the growth hormone secretagogue receptor type 1a (GHS-R1a) — the same Gq/11-coupled GPCR that binds endogenous ghrelin — expressed on anterior-pituitary somatotrophs and in the hypothalamic arcuate nucleus.5 Receptor activation drives the phospholipase-C to IP3/DAG to intracellular calcium cascade, triggering exocytosis of stored GH. This pathway is distinct from and additive to the GHRH pathway, which is why GHRP-2 plus GHRH together produce supra-maximal GH release.3 Because GHS-R1a is also present on hypothalamic NPY/AgRP neurons, GHRP-2 reproduces ghrelin's orexigenic (appetite-stimulating) action centrally.1

One root-cause caveat matters: unlike ipamorelin, the most receptor-selective GHRP, GHRP-2 is not endocrine-selective. At GH-releasing doses it also stimulates ACTH and cortisol to a degree comparable to human CRH, and raises prolactin.3 Any sustained, off-target activation of the cortisol axis is a meaningful downside for a compound being used cosmetically — and is part of why GHRP-2 never advanced as a chronic therapeutic. The GH response after a single dose is rapid (peak ~30–60 min) and short-lived, consistent with a brief plasma half-life; precise published human half-life figures are limited, so this monograph does not assert a specific numeric value absent a primary PK source.1

What is the evidence by indication?

GHRP-2's evidence is unusual among research peptides: its core use is genuinely Grade A in humans, while its marketed cosmetic uses are Grade D. The table below grades each indication honestly.

The diagnostic use is the headline. GHRP-2 reliably evokes a large, reproducible GH pulse; in the validated Japanese diagnostic, plasma GH after a single injection exceeds 15 µg/L in healthy subjects but stays below that threshold in severe GHD.2 In a retrospective cohort of 36 hypothalamic-pituitary patients (100 µg IV, sampling at 0/15/30/60 min), severe GHD was defined as a peak GH of 9 ng/mL or less.2 Head-to-head, GHRP-2 (1–2 µg/kg IV) released more GH than 1 µg/kg GHRH in both young and elderly adults.3 Across endocrinology, GHRP-2-based provocation sits among the validated stimulation tests for adult GHD, with sensitivity around 87–96% and specificity around 79–92% depending on protocol.6

Because GHRP-2 co-stimulates the ACTH–cortisol axis, the same test doubles as a screen for pituitary adrenal insufficiency. In the Suzuki cohort, an ACTH peak/baseline ratio of 1.55 or higher gave 83% sensitivity and 88% specificity, and combining it with a cortisol cutoff yielded 100% specificity for pituitary-origin adrenal insufficiency — which is why the authors recommend measuring ACTH during the GHRP-2 test.2

The appetite signal is real but tiny. In a randomized, double-blind, placebo-controlled crossover of 7 lean healthy men (1 µg/kg/h SC infusion over 270 min), GHRP-2 increased ad-libitum buffet caloric intake by 35.9 ± 10.9% (p=0.004) and raised pre-meal hunger, confirming ghrelin-like orexigenic activity in humans.1 But this is acute and underpowered (n=7); it does not establish GHRP-2 as a clinical appetite therapy, and the field advanced other agents (macimorelin, anamorelin, relamorelin) for related indications instead. Anti-inflammatory effects exist only in cell culture.7

What doses appear in the literature?

Reported strictly as information, not a protocol — and the only legitimate, approved use is the supervised diagnostic test. The approved Japanese diagnostic is a single 100 µg IV bolus in adults, with GH sampling at 0/15/30/60 minutes; the PMDA indication covers adults and children older than four years, and weight-based 1 µg/kg IV is also reported.212 Research pharmacology used 1 and 2 µg/kg IV to characterize GH, ACTH, cortisol and prolactin responses, while the appetite RCT used a 1 µg/kg/h continuous SC infusion.31 Intravenous, subcutaneous and intranasal routes were all explored in development.5 A key dose-ceiling note: human data indicate GH release plateaus while off-target cortisol and prolactin effects keep rising at higher exposures — pushing the dose buys side effects, not proportionally more GH.3

How safe is GHRP-2?

The dominant, well-documented issue is non-selectivity: at GH-releasing doses GHRP-2 transiently raises ACTH and cortisol (comparable to human CRH) and prolactin (lower than TRH).3 Acute single-dose diagnostic studies report it as generally well tolerated with no serious adverse events, with commonly described effects of flushing, warmth and hunger, plus transient impairment of glucose handling driven by the GH surge.2 The decisive limitation is that chronic safety is essentially uncharacterized — GHRP-2 was never developed as a chronic therapeutic, so the entire diagnostic evidence base is single-dose, and the off-target cortisol load with repeated cosmetic use is a specific, unquantified liability.1 Theoretical longer-term risks mirror the GH axis generally: promotion of growth signaling in occult or active malignancy, fluid retention, arthralgia, carpal-tunnel-type symptoms, and impaired glucose tolerance. Pregnancy and lactation lack safety data and should be avoided; pediatric use belongs only within the approved supervised diagnostic protocol.

What is the FDA and WADA status in 2026?

GHRP-2 is not FDA-approved for any indication — no NDA or BLA, and no validated indication, dosing or benefit-risk outside the Japanese diagnostic.8 On April 15, 2026, the FDA noticed the removal of 12 peptide bulk substances from 503A Category 2 (because nominators withdrew nominations) and scheduled PCAC meetings to consider adding peptides to the list.9 The July 23–24, 2026 PCAC agenda covers BPC-157, KPV, TB-500, MOTS-C, Emideltide/DSIP, Semax and Epitalon; an early-2027 meeting covers GHK-Cu, Melanotan II, LL-37, Dihexa acetate and PEG-MGF.10 Crucially, GHRP-2 is on neither docket and is identified by legal commentary — alongside GHRP-6, Melanotan II, LL-37 and PEG-MGF — as a substance expected to remain restricted due to cortisol/prolactin and GH-axis safety concerns. As of mid-2026 there is no near-term pathway to legal 503A compounding of GHRP-2.9

Outside the United States, the picture is split. Japan's PMDA approved GHRP-2 in October 2004 (Kaken's 'GHRP Kaken 100') as a single-dose diagnostic for GH deficiency in adults and children older than four — the only marketed regulatory approval worldwide, and the only GH secretagogue approved for any clinical use.25 The EMA has granted no marketing authorization. For athletes the rule is absolute: GHRP-2 is prohibited at all times under section S2.2.4 (Growth Hormone-Releasing Peptides) of the 2026 WADA Prohibited List, carries the strictest sanctions as a non-specified substance, and is detectable by LC-MS/MS.11

Bottom line. GHRP-2 is a well-characterized acute diagnostic peptide with a narrow, supervised legitimate use — a single IV dose that produces a large, reproducible GH pulse (Grade A) and a usable ACTH/cortisol readout (Grade B). Its appetite effect is real but rests on one tiny acute RCT (Grade B), and everything beyond diagnostics is unproven (Grade D): the therapeutic program was abandoned and the compound's non-selective cortisol and prolactin stimulation is a real liability for sustained use. Legally it sits at the restrictive end — unapproved by FDA/EMA, expected to remain restricted on the FDA compounding bulks list through the 2026–2027 PCAC cycle, and banned in sport at all times. Regulatory facts here are current as of June 2026 and should be re-verified after the July 23–24, 2026 PCAC meeting.