GHRP-2's only approval pepmg found is a one-time growth hormone test in Japan, and its largest treatment trial found no extra growth

Why this note exists

GHRP-2 is a six-amino-acid peptide that makes the pituitary release growth hormone by acting on the ghrelin receptor.[3][6][14] It came from a series of peptides made by Cyril Bowers's group at Tulane University and by Polygen in Germany; Kaken Pharmaceutical took the rights and sublicensed North America to Wyeth, whose U.S. phase 2 program in growth hormone deficiency "appears" to have been discontinued, according to a 2004 drug profile.[3] Its codes include GPA 748 and KP-102.[3]

Unlike most research peptides, it reached a regulator's approval. This note sets out what was approved, what the human trials found, and where it stands with FDA and in sport. Every status below was checked on October 15, 2026.

What Japan approved

One slow injection, then a blood test

Japan's drug regulator records approval of GHRP Kaken 100 for injection, pralmorelin hydrochloride, on October 22, 2004, for one indication: the diagnosis of growth hormone deficiency.[1] The current package insert, revised in July 2025, gives a single slow intravenous injection on an empty stomach: 100 micrograms for adults, and 2 micrograms per kilogram for ages 4 to under 18, capped at 100 micrograms above 50 kilograms.[2] It is contraindicated in pregnancy.[2] KEGG classes it among diagnostic reagents for endocrine function.[14]

The test works because healthy people respond strongly and people with deficiency do not. In the Japanese validation study, 77 healthy subjects and 58 patients whose growth hormone peaked below 3 µg/l on the insulin tolerance test received 100 micrograms intravenously. Peak growth hormone averaged 84.6 µg/l in healthy subjects against 1.36 µg/l in patients, and the authors set a diagnostic cut-off of 15 µg/l (9 µg/l against the recombinant WHO standard).[4]

In a 503-patient post-marketing survey run from 2006 to 2012 (502 analyzed for accuracy), the 9 ng/mL cut-off identified severe deficiency with a sensitivity of 0.853 and a specificity of 0.885 against doctors' diagnoses made with at least two other stimulation tests.[1] The same report says the drug was not approved or marketed outside Japan as of February 4, 2014.[1]

pepmg searched Drugs@FDA and openFDA's approved-drug data for pralmorelin, and ClinicalTrials.gov for pralmorelin, GHRP-2 and KP-102, on October 15, 2026; none returned an approved GHRP-2 product or a GHRP-2 study.[11][12] FDA's drug code directory does list GHRP-2 bulk powders, which is not an approval (see below).[15] Other countries' registers were not searched beyond the 2014 PMDA statement.

The treatment trials

Small studies looked promising. The large one did not.

The largest trial. Kaken also tested GHRP-2 as a treatment for short stature.[3] In a trial conducted at the company's request at 84 Japanese facilities, 126 prepubertal children with growth hormone deficiency were assigned by a double-blind method to placebo (44), a low dose (41) or a high dose (41) of GHRP-2 spray, twice daily for 48 weeks. Children under 20 kilograms received 50 or 100 micrograms per dose; heavier children received 100 or 200 micrograms.[5]

The spray worked on the pituitary: at baseline, mean peak growth hormone after a dose was 4.5 ng/ml on placebo, 13.2 on the low dose and 26.4 on the high dose.[5] But height SD scores changed by 0.07 on placebo, 0.03 on the low dose and 0.02 on the high dose, with no significant difference, and IGF-I did not differ significantly between groups.[5] The authors' explanation is exposure: each spray produced a brief pulse, and in the high-dose group the area under the growth hormone curve was 16.3 ng/ml·h against 230 in 12 other children given a growth hormone injection, though the two were measured at different time points.[5]

Earlier, smaller studies. In a 1997 study without a control group, 15 children with short stature took intranasal GHRP-2 two to three times daily; height velocity rose from 3.7 to 6.1 cm per year at six months, with no significant change in IGF-1.[6] In six children with growth hormone deficiency given daily injections under the skin at three rising doses over six months, growth velocity was higher during treatment, but IGF-I and IGFBP-3 did not rise.[7] In ten children given GHRP-2 by mouth for a year, seven reported more appetite in the first six months, and BMI did not change significantly.[8] None of these three had a placebo group.

From the published abstracts, and the full text of the 2014 trial.[4][5][6][9]

In intensive care. A Belgian study gave 14 adults with prolonged critical illness five days of GHRP-2 plus thyrotropin-releasing hormone and five days of placebo, in random order. IGF-I reached near-normal levels and markers of bone formation and protein breakdown shifted in an anabolic direction.[9] It measured hormones and biochemical markers, not survival or recovery.[9]

Safety and regulation

What the records report

In Japan's pre-approval trials of the diagnostic injection, 37.9% of 227 people had an adverse drug reaction, mainly stomach rumbling, a feeling of heat, sweating and a raised white blood cell count; the 503-patient survey recorded none, which the company attributed to closer monitoring in trials.[1] The current label puts the feeling of heat at 16.0%.[2] During the re-examination period, serious reactions were reported spontaneously in two patients, and all resolved; for one of them, the report names a missed hydrocortisone dose as a possible contributor.[1]

In the 126-child spray trial, 76 children (60.3%) had any adverse event, mostly unrelated illnesses such as upper respiratory infections, tonsillitis and ear infections. Events judged possibly or probably related were stomach rumbling in three children and nosebleed, lower blood pressure and raised eosinophils in one.[5]

FDA has listed GHRP-2 for injectable and nasal use as a substance that "may present significant safety risks" since September 29, 2023, in its 503B category for outsourcing facilities.[10] FDA cites possible immunogenicity "due to the potential for aggregation and peptide-related impurities," an unnatural amino acid that complicates characterization, and reports of "increased insulin requirement to maintain the blood glucose level, death of critically ill study subjects, infection and pancreatitis, though causality has not been established."[10] The one reference FDA links in that entry is the 14-patient intensive-care study, whose abstract does not report deaths; the page names no other source.[9][10] The page lists GHRP-2 under 503B only.[10]

FDA's National Drug Code directory, searched October 15, 2026, held four entries naming pralmorelin, all bulk-ingredient powders from four different labelers.[15] A directory listing is not an approval: FDA says inclusion "does not indicate that FDA has verified the information provided or that the products are FDA-approved."[16]

The 2026 World Anti-Doping Agency list names "GHRP-2 (pralmorelin)" among growth hormone-releasing peptides in class S2, prohibited at all times, in and out of competition.[13] Related compounds on that list include GHRP-6 and examorelin, also called Hexarelin .[13]

Three things this note is not saying

It is not saying GHRP-2 does nothing. It reliably raises growth hormone for a short time, which is exactly why it works as a diagnostic test.[4][5]

It is not saying the Japanese approval covers any other use. The approved product is a single diagnostic injection given by clinicians; the repeated-use trials were in children with growth hormone deficiency, not in healthy adults.[2][5]

It is not saying anything about vials sold as GHRP-2 outside pharmacies. The studies used manufacturer-supplied material; the 2014 trial's spray came from Kaken.[5] This note reports evidence and regulatory status, not medical advice.

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