GHRP-2

Pralmorelin, a synthetic six amino acid growth hormone secretagogue. It is approved in Japan only as a single-dose diagnostic test for growth hormone deficiency, and no regulator anywhere has approved it as a treatment.

Last updated: September 2026

What is GHRP-2?

GHRP-2, generic name pralmorelin, is a synthetic peptide of six amino acids that works as a growth hormone secretagogue: it binds the ghrelin receptor and prompts the pituitary gland to release a pulse of growth hormone (KEGG DRUG records its target as GHSR; PubChem lists GHRP-2 and pralmorelin as the same compound). It is one of the growth hormone peptides catalogued in our peptide library.

It is unusual among research peptides because it is a genuine, approved medicine, but in only one country and for only one narrow job. In Japan it is licensed as GHRP Kaken 100 for Injection, a single-dose diagnostic test for growth hormone deficiency, approved in 2004 and on sale since 2005 (approved Japanese label; manufacturer dossier). No other country has approved it. It is not an FDA-approved drug: a Drugs@FDA query returns no application for pralmorelin or GHRP-2. Development in the United States for treating growth hormone deficiency reached phase II under Wyeth and was discontinued (PMID 15230633). For how it sits among the other growth hormone peptides, see our HGH peptides guide.

Its popularity outside medicine comes from that growth hormone pulse, but the evidence does not support the physique and anti-ageing uses it is marketed for. No human study has shown GHRP-2 to improve muscle gain, fat loss, body recomposition, athletic performance, injury recovery or anti-ageing, and the one human study that did test sleep found no benefit: seven healthy young men given 1 microgram per kilogram as an intravenous bolus showed no enhancement of slow-wave sleep (trial dose, not a recommendation, PMID 9612233). As a treatment it has mostly disappointed: the growth hormone response fades within days of repeated dosing, IGF-I often does not rise, and a randomised 48-week trial in short children found no growth benefit over placebo (PMID 9820615; PMID 25374440). It is also prohibited in sport at all times by the World Anti-Doping Agency, and laboratories have repeatedly found that material sold as GHRP-2 is actually a different, counterfeit peptide (PMID 30136411).

How It Works

Ghrelin receptor agonist: GHRP-2 binds the growth hormone secretagogue receptor (GHSR), the same receptor as the natural hormone ghrelin, at roughly half the potency of ghrelin at the human receptor, and drives growth hormone release mainly through an action on the hypothalamus (KEGG DRUG target GHSR; Japanese manufacturer dossier).

Pituitary-dependent: in animals the growth hormone effect disappears when the pituitary is removed, which places its action on the pituitary axis rather than directly on muscle or other tissue (conscious rats and dogs, PMID 15646370).

Not growth hormone selective: in people it also raises ACTH, cortisol and prolactin, which is why the same injection is used to probe the adrenal and pituitary axes, not just growth hormone (healthy young adults, PMID 9285939).

Tachyphylaxis: the growth hormone response attenuates within days of repeated dosing. Peak GH fell from 83 to 51 mcg/L across five days of daily subcutaneous dosing in healthy men (PMID 9820615).

Ghrelin-like appetite effect: it increases food intake, mirroring ghrelin, which is the most consistent non-growth-hormone effect measured in healthy volunteers (PMID 15699539).

Benefits

Triggers a growth hormone pulse after a single dose, which is the basis of its approved Japanese diagnostic test (healthy subjects mean peak GH 84.60 ng/mL, range 15.88 to 345.06, n=89, approved Japanese label)
Separates growth hormone deficiency from a normal response: validated against the insulin tolerance test in adults (n=135, PMID 17609397; n=71, PMID 23079545), and distinguishing deficient from normal children by peak growth hormone (n=56, PMID 20662346)
Increases appetite and food intake over a single infusion in healthy volunteers, by about 10 to 36 percent depending on dose (PMID 15699539; PMID 16861611)
Raises IGF-I during continuous infusion, but not after a single or short daily course (older adults, 30-day infusion, PMID 15126555; healthy men, 5-day dosing showed no IGF-I rise, PMID 9820615)
Also releases ACTH, cortisol and prolactin, so it doubles as a pituitary and adrenal test and is not a pure growth hormone stimulus (young adults, PMID 9285939; healthy men, PMID 19907099)
No human study has measured muscle gain, fat loss, strength, or athletic performance from GHRP-2; the only body-composition data are from rodents, where chronic dosing added fat mass rather than lean mass (mice, PMID 11796511)

Dosing Described in Research and Labels

Phase	Dose	Frequency	Duration
Approved diagnostic test, adults 18+	100 mcg (approved Japanese label dose, single diagnostic test, not a recommendation)	Single slow intravenous injection, fasting	One administration, blood sampled to 60 min (approved Japanese label)
Approved diagnostic test, ages 4 to under 18	2 mcg/kg, or 100 mcg if body weight over 50 kg (approved Japanese label dose, single diagnostic test, not a recommendation)	Single slow intravenous injection, fasting	One administration (approved Japanese label)
Diagnostic validation, adults	100 mcg intravenous (trial dose, not a recommendation, PMID 17609397)	Single intravenous dose after overnight fast	One test, 2 h sampling, n=135 (PMID 17609397)
Diagnostic study, children	2 mcg/kg intravenous (trial dose, not a recommendation, PMID 20662346)	Single intravenous dose	One test, under 1 hour, n=56 (PMID 20662346)
Repeated dosing, healthy men	100 mcg subcutaneous, once daily (trial dose, not a recommendation, PMID 9820615)	Once daily, subcutaneous	5 days; GH response attenuated, IGF-I did not rise, n=9 (PMID 9820615)
Continuous infusion, older adults	1 mcg/kg/hour subcutaneous (trial dose, not a recommendation, PMID 15126555)	Continuous subcutaneous infusion	30 days; safety screening tests remained normal, n=17 (PMID 15126555)
Treatment attempt, GH-deficient children	0.3, 1.0, 3.0 mcg/kg/day subcutaneous, stepwise (trial dose, not a recommendation, PMID 9661608)	Daily subcutaneous, in 2-month steps	8 months; GH rose but IGF-I and IGFBP-3 did not, n=6 (PMID 9661608)
Controlled treatment trial, short children	50, 100, or 200 mcg intranasal (trial dose, not a recommendation, PMID 25374440)	Twice daily, intranasal	48 weeks; no significant growth difference vs placebo, n=126 (PMID 25374440)
Oral dosing, GH-deficient children	900 mcg/kg (trial dose, not a recommendation, PMID 14513874)	Twice daily, oral	12 months; transient appetite rise, no BMI effect, n=10 (PMID 14513874)
Appetite study, healthy men	1 mcg/kg/hour subcutaneous (trial dose, not a recommendation, PMID 15699539)	Continuous subcutaneous infusion, 270 min	Single session; food intake rose 35.9% vs saline, n=7 (PMID 15699539)
Animal study, GHRH-knockout mice	10 mcg (animal study, mice, subcutaneous, PMID 15985453)	Twice daily, subcutaneous	6 weeks; did not promote growth, worsened body composition (PMID 15985453)
Single case report, severe anorexia nervosa	Dose not stated in the abstract (single case report, no control group, PMID 26401470)	Intranasal before every meal	1 year of dosing; body weight rose 6.7 kg over 14 months, from 21.1 kg to 27.8 kg, with no obvious side effects reported

These figures summarise what published research and approved labels describe. They are educational, not a recommendation or a personal protocol. Any dose, schedule, or decision to use a compound belongs with a licensed prescriber.

Side Effects

Common

⚠Sensation of heat, the single most common reaction, listed at 16.0 percent on the approved Japanese label
⚠Borborygmi, that is audible bowel rumbling, listed at 5 percent or more on the label and the most frequent reaction in the pooled trials at 11.45 percent (approved Japanese label; Japanese manufacturer dossier)
⚠Sweating, 5.29 percent in the pooled trials (Japanese manufacturer dossier)
⚠Increased white blood cell count (leukocytosis), 5 percent or more on the label (approved Japanese label)
⚠Nausea, gastric discomfort, abdominal distension, thirst, cold sweat, hunger, malaise or unsteadiness, each 0.1 to under 5 percent (approved Japanese label)
⚠Somnolence, 0.1 to under 5 percent on the label and 1.76 percent in the pooled trials (approved Japanese label; Japanese manufacturer dossier)

Rare

•Hypotension, 0.1 to under 5 percent on the label and 0.44 percent in the pooled trials (approved Japanese label; Japanese manufacturer dossier)
•ALT elevation, abdominal pain, dizziness, bitter taste, back pain, headache or facial flushing, frequency unknown on the label (approved Japanese label)
•Label class warning: in patients with pituitary adenoma, similar drugs have been reported to cause pituitary apoplexy with visual and visual-field disturbance, headache and vomiting (approved Japanese label)
•Expected hormone effects rather than adverse events: ACTH, cortisol and prolactin rise after each dose, and in pituitary disease the ACTH rise can be very large, about 38-fold in one reported case (PMID 9285939; PMID 19707004)

Who Should NOT Use GHRP-2

✕Pregnant women or women who may be pregnant, the only formal contraindication on the approved Japanese label
✕Children under 4 years: the label states efficacy and safety trials were not conducted in low birth weight infants, newborns, infants or children under 4 (approved Japanese label)
✕Alongside other stimulation-test agents such as CRH, LH-RH or TRH: the label states the safety of concomitant use is not established (approved Japanese label)
✕Athletes in any tested sport: GHRP-2 is on the WADA Prohibited List at all times, in and out of competition, and has produced real positive tests and sanctions of up to two years (WADA 2026 Prohibited List; USADA sanction record)

What to Expect

Minutes

After a fasting intravenous dose, growth hormone peaks between 15 and 60 minutes, then clears quickly, with an elimination half-life of about 0.42 to 0.69 hours (approved Japanese label).

Days

Given daily for five days to healthy men, the growth hormone response fell across the period and IGF-I did not rise, which the authors described as significant response attenuation (PMID 9820615).

Weeks to months

A continuous 30-day infusion in older adults raised IGF-I to a plateau, while an 8-month subcutaneous course in growth-hormone-deficient children raised growth hormone but not IGF-I or IGFBP-3 (PMID 15126555; PMID 9661608).

48 weeks

A randomised, double-blind, placebo-controlled intranasal trial in 126 short children found no significant growth difference between GHRP-2 and placebo (PMID 25374440).

Notes from Ho Chi Minh City

If you go looking for GHRP-2 in Vietnam, the first thing worth knowing is what you will not find. Long Chau, the largest pharmacy chain, returns zero products for pralmorelin on its own site search, while the same search returns 288 results for paracetamol and 279 for somatropin the same day, so the gap is specific and not a broken search. Pharmacity and An Khang could not be read from this connection at all, so I claim nothing about what they do or do not list. What does circulate in Vietnamese is a piece of misinformation worth naming: a licensed Ho Chi Minh City polyclinic, Dripcare, publishes an article claiming GHRP-2 is approved by the FDA for muscle growth. The FDA Drugs@FDA database holds no approval for pralmorelin under any name, so that claim is simply false, and the article describes the peptide but does not say the clinic sells it. Outside the regulated channel the supply picture is worse than absent: three independent analytical papers from 2018 and 2019 found that material seized or bought as GHRP-2 was an N-terminal glycine analogue, a different molecule, not GHRP-2 (PMID 30051972; PMID 30136411; PMID 29864719). No certificate of analysis or third-party test for any GHRP-2 product turned up in the research base. Dose, route, and whether to touch any of this are decisions for a licensed prescriber, not for a search result.

Sourcing in Vietnam

GHRP-2 is not listed at Long Chau, and no Vietnamese retail price is published: Long Chau returns zero products for pralmorelin from a search that otherwise works, returning 288 results for paracetamol and 279 for somatropin the same day. Pharmacity and An Khang could not be read from here, which is a tooling limit and not evidence of absence, so nothing is claimed about them. There is a second reason to be wary of any quote: independent laboratories analysing seized and market-bought material repeatedly found an N-terminal glycine analogue rather than GHRP-2, and no certificate of analysis for any GHRP-2 product appears in the research base. It is also prohibited in sport at all times by WADA. Any sourcing, dose, or decision to use it belongs with a licensed prescriber.

FAQ

Q: Is GHRP-2 approved or legal?

A: GHRP-2 is approved only in Japan, and only as a single-dose diagnostic test for growth hormone deficiency, not as a treatment. It is not FDA-approved: a Drugs@FDA search returns no matching application. The FDA has considered it for pharmacy compounding and placed it in 503A Category 3, meaning nominated without adequate supporting evidence, which is different from being formally judged unsafe. In sport it is prohibited at all times by the World Anti-Doping Agency.

Q: Does GHRP-2 build muscle or burn fat?

A: No human study has tested GHRP-2 for muscle gain, fat loss, body recomposition, or athletic performance. The only body-composition data come from rodents, where chronic dosing increased fat mass rather than lean mass (mice, PMID 11796511). In growth-hormone-deficient children, an 8-month course raised growth hormone but not IGF-I, and a controlled 48-week trial found no growth benefit over placebo (PMID 9661608; PMID 25374440).

Q: What does GHRP-2 actually do in the body?

A: It binds the ghrelin receptor and triggers a short pulse of growth hormone, but it is not selective: it also raises ACTH, cortisol and prolactin, and it increases appetite, much like ghrelin (PMID 9285939; PMID 15699539). The growth hormone response also fades with repeated daily dosing (PMID 9820615).

Q: How is GHRP-2 used medically in Japan?

A: As a single fasting intravenous injection, 100 mcg in adults or 2 mcg per kg in children, to test whether the pituitary can release growth hormone; blood is sampled out to 60 minutes and a low peak points to deficiency (approved Japanese label). It is a diagnostic test, not a therapy. See the HGH peptides guide for how it compares with the other growth hormone peptides.

Q: Can you buy GHRP-2 at a pharmacy in Vietnam?

A: Not from Long Chau, the one Vietnamese chain we could read: it returns zero products for pralmorelin on its own site search, while the same search finds 288 results for paracetamol and 279 for somatropin the same day, so the gap is specific and not a broken search. Pharmacity and An Khang could not be read from our connection, so nothing is claimed about them. No Vietnamese registration or retail price for GHRP-2 was found. Anything sold as GHRP-2 outside a pharmacy is unverified, and labs have found counterfeit analogue material in the international grey market (PMID 30136411). See our peptide FAQ for more on sourcing and legality.

Where to Get GHRP-2 in Vietnam

GHRP-2 is not listed at Long Chau: its own site search returns zero products for pralmorelin, while the same search finds paracetamol and somatropin. Pharmacity and An Khang could not be read from our connection, so nothing is claimed about them, and no Vietnamese retail price is published. It is prohibited in sport at all times by WADA, and independent labs have found counterfeit glycine-analogue material sold as GHRP-2 in the international grey market. Review the supplier list and COA guide before any purchase decision.

View Supply Index COA & Purity Guide

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HGH Peptides Guide Ipamorelin CJC-1295 (DAC)CJC-1295 (no DAC)Tesamorelin Peptide Library

Research & Sources

GHRP Kaken 100 for Injection (pralmorelin hydrochloride): approved Japanese package insert, 3rd edition (revised July 2025) · Kaken Pharmaceutical Co., Ltd. · PMDA / KEGG MEDICUS (JAPIC) (2025) Link
Government-reviewed label: approved indication, posology, pharmacokinetics, and the adverse-reaction frequency table quoted on this page.
Interview Form (medicine dossier), GHRP Kaken 100 for Injection, 12th edition · Kaken Pharmaceutical Co., Ltd. · PMDA (2025) Link
Manufacturer dossier behind the label: mechanism, potency versus ghrelin, and the pooled adverse-reaction incidence table (227 trial cases plus 503 post-marketing cases).
KEGG DRUG D02040: Pralmorelin dihydrochloride · KEGG (Kyoto Encyclopedia of Genes and Genomes) (2026) Link
Target GHSR, molecular formula and mass, and the diagnostic efficacy classification.
PubChem Compound 6918245: Pralmorelin · NIH National Library of Medicine, PubChem (2026) Link
International Nonproprietary Name, synonyms (GHRP-2, KP-102, GPA-748), free-base formula and mass.
Pralmorelin: GHRP-2, GPA-748, growth hormone-releasing peptide-2, KP-102 · Drugs in R&D (2004) (PMID: 15230633)
Drug profile: Kaken and Wyeth rights, US phase II for GH deficiency, development discontinued.
A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency · European Journal of Endocrinology (2007) (PMID: 17609397)
Adult diagnostic validation, n=135, single 100 mcg intravenous dose after overnight fast.
Growth hormone response to GH-releasing peptide-2 in children · Journal of Pediatric Endocrinology & Metabolism (2010) (PMID: 20662346)
Children diagnostic study, n=56, single 2 mcg/kg intravenous dose.
The arginine and GHRP-2 tests as alternatives to the insulin tolerance test for the diagnosis of adult GH deficiency in Japanese patients: a comparison · Endocrine Journal (2013) (PMID: 23079545)
Head-to-head against the insulin tolerance test, n=71 adults; dose not stated in the abstract.
A five day treatment with daily subcutaneous injections of growth hormone-releasing peptide-2 causes response attenuation and does not stimulate insulin-like growth factor-I secretion in healthy young men · European Journal of Endocrinology (1998) (PMID: 9820615)
Healthy men, n=9, 100 mcg subcutaneous daily for 5 days; peak GH fell 83 to 51 mcg/L, IGF-I did not rise.
Sustained elevation of pulsatile GH secretion and IGF-I, IGFBP-3 and IGFBP-5 during 30-day continuous subcutaneous infusion of GH-releasing peptide-2 in older men and women · Journal of Clinical Endocrinology & Metabolism (2004) (PMID: 15126555)
Older adults, n=17, 1 mcg/kg/hour continuous subcutaneous infusion, 30 days; safety screening tests remained normal.
Effects of eight months treatment with graded doses of a growth hormone (GH)-releasing peptide in GH-deficient children · Journal of Clinical Endocrinology & Metabolism (1998) (PMID: 9661608)
GH-deficient children, n=6, 0.3 to 3.0 mcg/kg/day subcutaneous, 8 months; GH rose but IGF-I and IGFBP-3 did not.
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 · Clinical Pediatric Endocrinology (2014) (PMID: 25374440)
Randomised, double-blind, placebo-controlled intranasal trial, n=126, 48 weeks; no significant growth difference versus placebo.
Changes in appetite and body weight in response to long-term oral administration of the ghrelin agonist GHRP-2 in growth hormone deficient children · Journal of Pediatric Endocrinology & Metabolism (2003) (PMID: 14513874)
GH-deficient children, n=10, 900 mcg/kg oral twice daily, 12 months; transient appetite rise, no chronic BMI effect.
Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men · Journal of Clinical Endocrinology & Metabolism (2005) (PMID: 15699539)
Healthy lean men, n=7, 1 mcg/kg/hour subcutaneous infusion; food intake rose 35.9% versus saline.
Obese subjects respond to the stimulatory effect of the ghrelin agonist growth hormone-releasing peptide-2 on food intake · Obesity (2006) (PMID: 16861611)
Lean and obese subjects, n=19, randomised; food intake rose 10.2% at low dose and 33.5% at high dose.
Effects of GHRP-2 and hexarelin on GH, prolactin, ACTH and cortisol levels in man · Peptides (1997) (PMID: 9285939)
Young adults, n=6, 1 and 2 mcg/kg intravenous; GHRP-2 is not fully specific, raising PRL, ACTH and cortisol as well as GH.
GH-releasing peptide-2 does not stimulate arginine vasopressin secretion in healthy men · Endocrine Journal (2010) (PMID: 19907099)
Healthy men, n=10, 100 mcg intravenous; significant GH, ACTH and PRL peaks with no change in blood pressure or osmolality.
Exaggerated response of adrenocorticotropic hormone to growth hormone-releasing peptide-2 test in Cushing disease (case report) · Neurologia medico-chirurgica (2009) (PMID: 19707004)
Single case: ACTH rose from 66 to 2490 pg/mL, about 38-fold, after 100 mcg GHRP-2.
Pharmacological characteristics of KP-102 (GHRP-2), a potent growth hormone-releasing peptide · Arzneimittel-Forschung (2004) (PMID: 15646370)
Conscious rats and dogs: GH-releasing activity absent in hypophysectomized rats, confirming a pituitary-dependent action; doses not stated in the abstract.
Effects of long-term treatment with growth hormone-releasing peptide-2 in the GHRH knockout mouse · American Journal of Physiology: Endocrinology and Metabolism (2005) (PMID: 15985453)
GHRH-knockout mice, 10 mcg subcutaneous twice daily, 6 weeks; did not promote longitudinal growth and worsened body composition.
GH-releasing peptide-2 increases fat mass in mice lacking NPY · Endocrinology (2002) (PMID: 11796511)
Mice, daily subcutaneous dosing; increased fat mass and bone mass but not lean mass; doses not stated in the abstract.
Drugs@FDA database query for pralmorelin and GHRP-2 (no approved application found) · US Food and Drug Administration · openFDA / Drugs@FDA (2026) Link
Returns NOT_FOUND for pralmorelin, GHRP-2 and growth hormone releasing peptide; a somatropin control on the same endpoint returns approved products, so the null is genuine.
Bulk Drug Substances Nominated for Use in Compounding Under Section 503A (Category 3: Nominated Without Adequate Support), updated 14 May 2026 · US Food and Drug Administration · FDA (2026) Link
GHRP-2 and GHRP-6 appear in Category 3, nominated without adequate support, which is separate from the Category 2 safety-concern list.
World Anti-Doping Code International Standard Prohibited List 2026 (section S2.2.4) · World Anti-Doping Agency · WADA (2026) Link
Names GHRP-2 (pralmorelin) among GH-releasing peptides, prohibited at all times, in and out of competition.
USADA sanction announcement: GHRP-2 positive test (22-month sanction) · US Anti-Doping Agency · USADA (2021) Link
A real-world positive test for GHRP-2 and its metabolite; one of several documented sanctions.
Identification of a novel growth hormone releasing peptide (a glycine analogue of GHRP-2) in a seized injection vial · Drug Testing and Analysis (2019) (PMID: 30051972)
Seized injection vial contained a glycine analogue of GHRP-2, not GHRP-2.
Glycine-modified growth hormone secretagogues identified in seized doping material · Drug Testing and Analysis (2019) (PMID: 30136411)
Danish customs seizures: powders sold as GHRP-2 and others were N-terminal glycine analogues.
Analysis of new growth promoting black market products · Growth Hormone & IGF Research (2018) (PMID: 29864719)
Black-market products contained Gly-GHRP-2 and other N-terminal glycine analogues.
Long Chau (FPT Long Chau) on-site search for pralmorelin (0 products) with paracetamol and somatropin controls · Nha thuoc FPT Long Chau · nhathuoclongchau.com.vn (2026) Link
Pralmorelin returns totalCount 0; paracetamol returns 288 and somatropin 279 the same day, so the zero is a specific product gap, not a broken search.
Dripcare polyclinic article, Tiem peptide de tang truong co bap (describes GHRP-2) · Dripcare Cell Anti-Ageing Institute (HCMC licence 09966/HCM-GPHD) · dripcare.vn (2026) Link
A licensed Vietnamese clinic article that describes GHRP-2 and carries the false claim that it is FDA-approved for muscle growth; the page does not state the clinic sells it.
Evidence against a role for the growth hormone-releasing peptide axis in human slow-wave sleep regulation · The American Journal of Physiology (1998) (PMID: 9612233)
Randomized crossover in seven young healthy men, 1 mcg/kg intravenous bolus; no effect on sleep and no enhancement of slow-wave sleep. The one human sleep test of GHRP-2, and it was negative.
One-year intranasal application of growth hormone releasing peptide-2 improves body weight and hypoglycemia in a severely emaciated anorexia nervosa patient · Journal of Cachexia, Sarcopenia and Muscle (2015) (PMID: 26401470)
Single case report, no control group; intranasal before every meal for 1 year, body weight rose 6.7 kg over 14 months with no obvious side effects reported. Dose not stated in the abstract.

Important Disclaimer

Educational content only. Not medical advice. Peptides discussed on this page are not approved by Vietnam’s Ministry of Health (Bộ Y Tế) or the Drug Administration of Vietnam (DAV) for the indications described. Research peptides are not stocked at Long Châu, Pharmacity, or any retail pharmacy in Vietnam. Consult a licensed physician before any use.