Published human work used a single intravenous bolus for diagnosis . Research used subcutaneous infusion at 1 microgram per kilogram per hour . The paediatric trial used a nasal spray . As reported on bodybuilding forums catalogued in a 2026 clinical review: 100 to 150 micrograms subcutaneously, two or three times daily, fasted . Cycles run eight to twelve weeks. Convention, not guidance.

GHRP-2: uses, evidence and status | Inside Your Peptides

compound file

The answer, first. A synthetic hexapeptide that activates the ghrelin receptor to release growth hormone. Described in the early 1990s, approved in Japan in 2004 as a diagnostic agent. The strongest evidence is for growth hormone deficiency testing, graded A — approval or replicated trials.

A single 100-microgram intravenous dose peaked serum GH within 60 minutes in every subject. Peak GH was 84.6 micrograms per litre in 77 healthy adults against 1.36 in 58 deficient patients ¹.

Approved in Japan for this ⁷¹³. The rest of what it is sold for — muscle gain or recomposition, linear growth in GH deficiency — grade D or E: animal or mechanism data only, or a claim the human trials have already tested and not supported.

What it is used for

Every use graded on its own evidence, not the compound as a whole. 5 outcomes, ranked by what the human record supports.

#outcome · human · animal · gradewhat the best evidence actually shows

01Growth hormone deficiency testing135 adults, plus approval · extensivegrade AA single 100-microgram intravenous dose peaked serum GH within 60 minutes in every subject. Peak GH was 84.6 micrograms per litre in 77 healthy adults against 1.36 in 58 deficient patients ¹. Approved in Japan for this ⁷¹³.

02Sustained GH and IGF-I elevation17 older adults, 30 days · supportinggrade CContinuous subcutaneous infusion at 1 microgram per kilogram per hour raised pulsatile GH more than threefold on day 1 and 1.8-fold on day 30 ². IGF-I held a stable plateau. Seventeen older adults, no parallel control arm.

03Appetite and food intake7 lean men, then obese adults · consistentgrade CSeven lean men infused for 270 minutes ate 35.9 percent more at a buffet than on saline, every subject increasing intake ³. Replicated in obese adults ¹⁰ and over months of oral dosing in children ¹⁴. Single meals.

04Muscle gain or recompositionno trial · mechanism onlygrade DNo trial has measured lean mass, fat mass or strength on GHRP-2. The human record is hormone concentrations and appetite ²³. A 2026 clinical review places the whole secretagogue class at the same gap ⁸.

05Linear growth in GH deficiency126 children, randomised · not applicablegrade ERaising endogenous GH did not produce growth. Intranasal GHRP-2 twice daily for 48 weeks in 126 GH-deficient children moved height 0.02 to 0.03 standard deviations against 0.07 on placebo ⁴. IGF-I did not move.

gradewhat it means

ARegulatory approval, or multiple adequately-powered trials agreeing with each other

BAt least one well-powered human randomised trial, with the direction replicated

CSmall or open-label human trials only

DAnimal or mechanism data only, with no controlled human outcome

EA claim the human trials have already killed

How it works

The proposed mechanism, in three steps. A mechanism is a reason to run a trial, never a substitute for one.

1targetBinds the growth hormone secretagogue receptor GHSR-1a on the hypothalamus and anterior pituitary, the same receptor ghrelin uses.

2signalDrives pituitary GH release and synergises with growth hormone releasing hormone rather than replacing it, so both pathways stay intact.

3effectGH rises within minutes and clears within two hours. Prolactin, ACTH and cortisol rise alongside it.

What it does not do

Claims the current record does not support. Worth knowing before you set expectations.

not supported by the evidence

Raises IGF-1 the way growth hormone does. Forty-eight weeks of nasal dosing in 126 children left IGF-I unchanged ⁴. Route limits exposure, but no injected regimen has been trialled to an outcome.
Builds muscle. No trial has measured muscle on GHRP-2. Raising GH produced no growth outcome in the one placebo-controlled trial that measured one ⁴.
Selective, hits only growth hormone. At 1 to 2 micrograms per kilogram its ACTH and cortisol response matched that of corticotropin-releasing hormone ⁵.
Safe because it is only a peptide. FDA cites reports of increased insulin requirement, infection, pancreatitis and death in critically ill recipients, causality unestablished ⁹.

How it is used

What published protocols administered, and what the community reports doing. Descriptive on both counts, and never a recommendation.

routeSubcutaneous injection in the community record. Published human work used intravenous bolus, subcutaneous infusion, oral dosing and a nasal spray.

formatLyophilised powder in a multi-dose vial, reconstituted with bacteriostatic water. Sold by the milligram.

published dosesThe Japanese diagnostic protocol is a single 100-microgram intravenous dose ¹. Research infusions ran 1 microgram per kilogram per hour subcutaneously, for 24 hours up to 30 days ²³. The 48-week paediatric trial used 50 to 200 micrograms intranasally twice daily ⁴.

human pharmacokineticsTerminal half-life 0.55 hours, clearance 0.66 litres per hour per kilogram, from a phase I study in children ⁶.

reported conventionsAs reported on bodybuilding forums catalogued in a 2026 clinical review, 2025 to 2026: 100 to 150 micrograms subcutaneously, two or three times daily, fasted. Cycles run eight to twelve weeks ⁸. That review presents these as behavioural data, not treatment strategies. Convention, not guidance.

commonly paired withCJC-1295

This site does not publish protocols to follow. The doses above are what studies administered or what users report, stated as facts about the literature and the market. How protocols are structured, mixing and storage and the reconstitution calculator cover the arithmetic.

What to expect

Where a trial measured it, the trial. Where only the community reports it, that is said out loud.

onsetSerum GH peaks within 60 minutes of an intravenous dose in every subject tested ¹, and near 25 minutes in the paediatric pharmacokinetic study ⁶. Food intake rose across a 270-minute infusion ³. No trial has measured how long any downstream change takes.

most common reportAs reported: hunger inside the hour. The two effects human trials measured are a short GH pulse and increased food intake.

adverse effectsProlactin, ACTH and cortisol rise with the GH pulse, the cortisol response matching corticotropin-releasing hormone at 1 to 2 micrograms per kilogram ⁵. FDA cites reports of increased insulin requirement, infection, pancreatitis and death in critically ill recipients, causality unestablished ⁹.

the stop signalNo trial defined a stop rule. FDA's named concerns are dysglycaemia and immunogenicity ⁹. The 2026 review treats rising fasting glucose, and cortisol or prolactin abnormalities, as the signals to retest after withdrawal ⁸.

Approval and status

What regulators and sport bodies have actually said, separately from what the evidence shows.

approvalApproved in Japan since 2004 as pralmorelin, GHRP Kaken 100, a diagnostic agent only ⁷¹³.

FDANot approved in the United States. On FDA's compounding category 2 list since 29 September 2023 for injectable and nasal routes ⁹.

sport [WADA]Prohibited at all times under S2.2.4, named as pralmorelin ¹¹.

sold asresearch chemical

Check the vial

The grade above describes a molecule studied under controlled conditions. It says nothing about the powder in a particular vial.

That gap is the one part of this market a reader can actually close. How to read a certificate of analysis covers the five measures in five minutes, and the 2026 audit grades vendors on the documents they publish against a rubric printed in full.

Questions we get

What is GHRP-2 used for?

One approved use and several unapproved ones. In Japan it is a diagnostic agent: a single 100-microgram intravenous dose separates GH-deficient adults from healthy ones, 1.36 against 84.6 micrograms per litre ¹⁷.

Off-label it is bought to raise growth hormone and to raise appetite. Seven lean men infused with it ate 35.9 percent more at a buffet meal ³. No trial has measured muscle, fat or strength.

How is GHRP-2 used?

Published human work used a single intravenous bolus for diagnosis ¹. Research used subcutaneous infusion at 1 microgram per kilogram per hour ².

The paediatric trial used a nasal spray ⁴. As reported on bodybuilding forums catalogued in a 2026 clinical review: 100 to 150 micrograms subcutaneously, two or three times daily, fasted ⁸. Cycles run eight to twelve weeks. Convention, not guidance.

How long does GHRP-2 take to work?

The hormone moves in minutes. Serum GH peaks inside 60 minutes of an intravenous dose in every subject tested, and the peptide's own half-life is about 33 minutes ¹⁶.

Appetite rose across a 270-minute infusion ³. How long a body-composition change takes has never been measured, because no trial has looked. The one placebo-controlled outcome trial, 48 weeks in children, found no benefit ⁴.

Is GHRP-2 an approved drug?

Partly, and not where most buyers live. Japan approved it in 2004 as pralmorelin, brand name GHRP Kaken 100, a single-dose diagnostic agent for growth hormone deficiency ⁷¹³.

It has no therapeutic approval anywhere. In the United States it is unapproved and sits on FDA's compounding category 2 list for injectable and nasal routes, added 29 September 2023 ⁹. What is sold online is a research chemical.

Will GHRP-2 show up on a drug test?

Yes, if the test looks for it. It is prohibited at all times under section S2.2.4 of the 2026 prohibited list, named as pralmorelin ¹¹.

Validated urine methods exist, and after a single nasal dose in one volunteer GHRP-2 and two of its metabolites stayed detectable for 47 hours ¹². That is one volunteer by a nasal route, so treat it as an order of magnitude.

References

Chihara K, Shimatsu A, Hizuka N, et al. A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency. Eur J Endocrinol. 2007;157:19-27. PMID 17609397
Bowers CY, Granda R, Mohan S, et al. Sustained elevation of pulsatile growth hormone secretion and IGF-I, IGFBP-3 and IGFBP-5 concentrations during 30-day continuous subcutaneous infusion of GH-releasing peptide-2 in older men and women. J Clin Endocrinol Metab. 2004;89:2290-2300. PMID 15126555
Laferrere B, Abraham C, Russell CD, Bowers CY. Growth hormone releasing peptide-2, like ghrelin, increases food intake in healthy men. J Clin Endocrinol Metab. 2005;90:611-614. PMID 15699539
Tanaka T, Hasegawa Y, Yokoya S, Nishi Y. Increased secretion of endogenous GH after treatment with an intranasal GH-releasing peptide-2 spray does not promote growth in short children with GH deficiency. Clin Pediatr Endocrinol. 2014;23:107-114. PMID 25374440
Arvat E, di Vito L, Maccagno B, et al. Effects of GHRP-2 and hexarelin, two synthetic GH-releasing peptides, on GH, prolactin, ACTH and cortisol levels in man. Peptides. 1997;18:885-891. PMID 9285939
Pihoker C, Kearns GL, French D, Bowers CY. Pharmacokinetics and pharmacodynamics of growth hormone-releasing peptide-2: a phase I study in children. J Clin Endocrinol Metab. 1998;83:1168-1172. PMID 9543135
Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN. Drugs R D. 2004;5:236-239. PMID 15230633
Dominikowski A, Rekos Z, Olejarz M, et al. The emerging landscape of performance-enhancing peptides modulating the GH-IGF1 axis. Front Endocrinol. 2026;17:1822475. PMID 42395176
US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. Content current as of 22 April 2026. fda.gov
Laferrere B, Hart AB, Bowers CY. Obese subjects respond to the stimulatory effect of the ghrelin agonist growth hormone-releasing peptide-2 on food intake. Obesity [Silver Spring]. 2006;14:1056-1063. PMID 16861611
World Anti-Doping Agency. Prohibited List 2026, International Standard. wada-ama.org
Semenistaya E, Zvereva I, Thomas A, et al. Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, hexarelin and ipamorelin. Drug Test Anal. 2015;7:919-925. PMID 25869809
National Center for Advancing Translational Sciences. Inxight Drugs record for pralmorelin: approved, marketing name GHRP Kaken 100, assessment of growth hormone deficiency. drugs.ncats.io
Mericq V, Cassorla F, Bowers CY, et al. Changes in appetite and body weight in response to long-term oral administration of the ghrelin agonist GHRP-2 in growth hormone deficient children. J Pediatr Endocrinol Metab. 2003;16:981-985. PMID 14513874

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