GHRP-2 Is an Approved Drug in Japan, and the Approval Covers One Injection

The five other names it hides behind

GHRP-2 is a lab built chain of six amino acids, an analogue of GHRP-6 rather than a form of ghrelin, and it circulates under at least six names: GHRP-2, pralmorelin, which is the international nonproprietary name, KP-102 with its formulation codes KP-102D and KP-102LN, GPA-748, and the Japanese trade name GHRP Kaken 100 (PMID 15230633). Search only for GHRP-2 and you miss the entire Japanese regulatory file, so go and run the search for pralmorelin instead. Its evidence also has to be kept apart from hexarelin's and ipamorelin's (PMID 9285939).

Arvat and colleagues, 1997, gave 1 and 2 mcg/kg intravenously to six normal young adults and 2 mcg/kg to six elderly subjects, and prolactin, ACTH and cortisol rose along with growth hormone, the authors saying plainly that the compound is not fully specific (PMID 9285939). The best replicated effect in healthy adults is appetite: seven lean healthy men on a 270 minute subcutaneous infusion at 1 mcg/kg/h ate 35.9 percent more at a buffet meal than on saline (PMID 15699539), and 19 subjects, ten lean and nine obese, on double blind subcutaneous infusions ate 33.5 percent more at 1 mcg/kg/h and 10.2 percent more at 0.1 mcg/kg/h than on placebo (PMID 16861611).

Five days, and thirty days

Nijland used the community's dose, route, frequency and demographic, which makes it the most relevant human study there is. Nine healthy young men, 100 mcg subcutaneously once daily for five days. Peak growth hormone fell from a mean of 83 mcg/L on day 1 to 59 on day 3 and 51 on day 5, and mean serum IGF-I did not move at all, sitting at 22, 25, 23, 25, 23 and 24 nmol/L on days 1 to 6 (PMID 9820615). That flat IGF-1 held over far longer runs in children, across eight months of escalating subcutaneous doses from 0.3 to 3.0 mcg/kg/day in six growth hormone deficient children who grew faster all the same (PMID 9661608), and over 18 to 24 months of intranasal dosing in children with short stature (PMID 9390009).

Now the exception, and the study most often reached for when somebody quotes a rise in IGF-1. Five men and five women, older, with decreased growth hormone secretion and low IGF-1, received 1 mcg/kg/h by continuous subcutaneous infusion for 30 days, and pulsatile growth hormone and serum IGF-1 were both up after 24 hours and both stayed up for the full 30 days (PMID 11322505). That same paper also reports acute bolus doses of 0.1, 1 and 10 mcg/kg; its abstract describes the acute comparisons as intravenous boluses and specifies the subcutaneous route only for the 10 mcg/kg dose.

A pump is not an injection. Picture a bath with the plug out: a trickle left running all month holds the level, and a few hard bursts a day drain away in between. That picture is mine, not a published mechanism, and I found no paper stating the pattern explicitly. The intensive care work sits on the infusion side of it: twenty-six critically ill adults averaging 63 years in a randomised crossover, twenty-two given GHRP-2 as a 1 mcg/kg intravenous bolus then 1 mcg/kg/h intravenously for 21 hours, with serum IGF-I up 61 percent within 24 hours (PMID 9024260).

The citation that sent me back to the ipamorelin entry

One community dosing guide credits the desensitisation finding to "Raun et al., Growth Horm IGF Res (1998)" while linking PMID 9820615, which is Nijland in the European Journal of Endocrinology. Raun 1998 is a different paper, and it is the ipamorelin swine study, so a GHRP-2 cycling protocol is being justified by a citation that, read literally, points at a pig experiment on a different molecule. Following it corrected this site. The ipamorelin entry said that pig study recorded nothing for GHRP-2. The abstract says otherwise: both GHRP-6 and GHRP-2 raised ACTH and cortisol in those pigs, ipamorelin did not, and that is precisely the axis on which ipamorelin was found to differ (PMID 9849822). What that assay produced a null for, across every compound in it, was prolactin.

The Japanese label, and what a label gets you

GHRP-2 is the only growth hormone secretagogue in this reference with an approved medicinal product anywhere that I could find. In Japan it is sold as GHRP Kaken 100 for injection, generic name pralmorelin hydrochloride, by Kaken Pharmaceutical, indicated for the diagnosis of growth hormone secretion deficiency, marketed since February 2005 with the label last revised in July 2022. The approved dose is one slow intravenous injection given fasting, 100 mcg from age 18, and 2 mcg/kg capped at 100 mcg from age 4 to under 18. A single administration, as a test.

The label lists real adverse reactions with frequencies attached, which is more than anything else in this reference offers. I opened the current package insert and read the table myself, because two automated readings of it had disagreed about which reaction sits in which band. Three things sit at 5 percent or more: borborygmus, a raised white cell count, and a sensation of heat at 16.0 percent. At 0.1 to under 5 percent, hypotension, nausea, gastric discomfort, abdominal distension, somnolence, rhinorrhoea, sweating, thirst, cold sweat, malaise, unsteadiness, and a sensation of hunger. At unknown frequency, raised ALT, abdominal pain, dizziness, a bitter taste, back pain, headache, facial flushing and shifts in the white cell differential. Note which one hunger is. It is a sensation of hunger rather than a decrease in appetite, and it is a quantified reaction rather than an unquantified one. All of it is one intravenous dose under supervision, not a record of a repeated subcutaneous habit.

The convention that circulates differs in route and frequency: 100 to 300 mcg per injection, subcutaneously, one to three times daily, most commonly 200 mcg, taken fasted and cycled. I could not establish any derivation for it, beyond noting that it lands on the same 100 mcg as the Japanese diagnostic dose and the Nijland protocol, with nobody appearing to have reasoned from either.

What nobody has looked at

Body composition. Across roughly 250 PubMed records I found no human trial with body composition, lean mass, fat mass, muscle size, strength, athletic performance, recovery or injury healing as a measured outcome. The one study aimed at the people who actually buy this is a retrospective chart review of men on testosterone therapy given GHRP-2 alongside GHRP-6 and sermorelin, which reported IGF-1 rising and measured only serum hormones (PMID 28830317). I found no registered study of GHRP-2 anywhere on ClinicalTrials.gov either, and no published carcinogenicity, genotoxicity or repeat dose toxicology study. The longest nonclinical dosing I found is six weeks, 10 mcg subcutaneously twice a day in GHRH knockout mice, where the peptide failed to restore growth and worsened the body composition abnormalities of growth hormone deficiency (PMID 15985453).

Regulators

WADA names it explicitly and by both names under S2.2.4 of the 2026 Prohibited List effective 1 January 2026, prohibited at all times and non-Specified, the tier carrying a four year default sanction. In the United States it is not approved and it is not on the 503A bulks list, sitting in Category 3, nominated without adequate support, which means FDA never evaluated it at all. One note on my sourcing there: fda.gov returned 404 to every automated attempt I made, so I confirmed the Category 3 placement from an archived edition, and I have left the list revision dates out rather than print numbers I have not seen in a browser. As for what is in the vial, the Cologne analysts who found an extra glycine on black market ipamorelin found it on GHRP-2 too (PMID 29864719).

My opinion

The label is what makes this compound different, and it argues against the sales pitch rather than for it. Everywhere else in this reference I am reporting the absence of safety data, and here a regulator has a printed table with percentages on it, describing what one injection into a vein does when it is given fasting, under supervision, to find out whether a pituitary works. That is the entire approved use in the one country I found an approval in, and it says nothing about the second dose.

The IGF-1 split is the finding I would want a buyer to sit with. Dosed intermittently, it did not move over five days of injections in healthy men, over eight months of injections in deficient children, or over 18 to 24 months through the nose. It moved under a 30 day pump and under an intravenous drip in intensive care. Nobody runs a pump.

If you have run GHRP-2, I want to know whether your appetite changed on it and how quickly, because that is the effect the trials found twice and the label prints, and it is the one nobody sells it on.

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This content is for educational and informational purposes only and is not medical advice. Peptides discussed are research compounds and may not be approved for human use. Nothing here should be used to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before starting any peptide, supplement, or protocol. Individual responses vary. Do not self-administer compounds without proper medical supervision.