What is GHR-2 (GHRP-2)?

GHRP-2 is a synthetic growth hormone-releasing peptide that acts as a ghrelin/GHS receptor agonist. It stimulates pituitary GH release and is part of the older GHRP family that includes GHRP-6, GHRP-2, hexarelin, and ipamorelin.[8][6][9]

GHRP-2 is generally more potent for GH release than GHRP-6 and less selective than ipamorelin, with more cortisol and prolactin concern than the cleaner GHRP profile.[6][9]

GHRP-2 naming often overlaps with pralmorelin, KP-102, and growth hormone-releasing peptide-2. Those names point to the same ghrelin-receptor secretagogue family, but they do not make GHRP-2 interchangeable with GHRP-6, ipamorelin, or GHRH analogs.[8][6]

What GHR-2 (GHRP-2) is investigated for

GHR-2 (GHRP-2) evidence is grouped by practical use case and injectable route context.Each use case separates confidence, human evidence, animal or mechanistic support, and the practical takeaway.

GH release and IGF-1 response

Injectable

60%Emerging

GHRP-2 is best framed as a GH secretagogue with limited long-term outcome evidence.[6][33][9][12][28]

Human evidence

Human studies support GH and IGF-1 response and diagnostic testing, but not long-term fat-loss, lean-mass, sleep, recovery, or wellness outcomes.[6][33][10]

Animal / mechanistic evidence

Animal and cell studies support ghrelin/GHS receptor biology and pituitary GH release.[6][30][34]

Appetite and food-intake signaling

Injectable

56%Emerging

Appetite stimulation can be useful in wasting contexts or undesirable for fat-loss goals, so the same signal should not be framed as a universal benefit.[6][9]

Human evidence

Human studies show GHRP-2 can increase food intake in obese subjects, with effects that depend on compound, dose, and population.[6][9]

Animal / mechanistic evidence

Ghrelin-receptor biology directly supports appetite signaling.[6][9]

Fat loss and lean mass

Injectable

28%Limited

Fat-loss and lean-mass claims remain indirect GH-axis hypotheses rather than demonstrated GHRP-2 outcomes.[6][28]

Human evidence

Human GH/IGF-1 response data do not establish durable fat-mass or lean-mass outcomes with GHRP-2.[6][33]

Animal / mechanistic evidence

Interest in fat-mass and lean-mass outcomes is extrapolated from GH-axis pharmacology and animal growth or tissue models.[3][4][28]

Training recovery

Injectable

26%Limited

Training recovery should be displayed as a separate, low-confidence tissue-model claim.[28][40]

Human evidence

Controlled human recovery endpoints, return-to-training data, and injury-repair outcomes are not established for GHRP-2.[6][33]

Animal / mechanistic evidence

A rat rotator-cuff tendon-bone healing model supports a tissue-recovery rationale, but it does not prove athlete recovery in people.[28][17]

Sleep quality

Injectable

16%Insufficient

Sleep quality is a common GHRP-2 tracking claim, but current evidence supports GH-axis signaling rather than a proven sleep benefit.[6][28]

Human evidence

Controlled human sleep-quality, insomnia, sleep-stage, or deep-sleep outcome trials are not established for GHRP-2.[6][33]

Animal / mechanistic evidence

The sleep rationale is indirect, based on GH-pulse physiology rather than a dedicated sleep mechanism.[6]

Evidence snapshot

Overall confidence

Emerging

56%

GHRP-2 has credible human GH-secretagogue data and ghrelin-receptor pharmacology. Practical confidence is limited by missing approved therapeutic use and long-term outcome trials.[6][33][9]

Overall confidence is a page-level composite, not an average; it weighs evidence quality, route/molecule match, and practical limitations.

55%

Human evidence

Emerging

Available human studies support GH and IGF-1 response, food-intake effects, diagnostic testing, and anti-doping detection. They do not establish long-term wellness outcomes.[6][33][9]

46%

Animal / preclinical

Preliminary

Animal and cell studies support ghrelin/GHS receptor biology, food intake, inflammation, and tissue-model hypotheses. Those findings remain secondary to human endocrine limits.[12][28]

65%

Mechanism support

Moderate

Ghrelin/GHS receptor activation directly explains GH release, appetite effects, and off-target endocrine monitoring. Mechanistic confidence is stronger than outcome confidence.[6][9]

Forms & administration

GHRP-2 is usually discussed as a short-acting injectable GH-axis protocol. Timing, food spacing, appetite effects, and lab context matter because the goal is a GH pulse.[6][33][9]

Injectable

Dosing & protocols

These ranges are general reference points, not personal dosing instructions.

Typical Range

Injectable protocols use 100-300 mcg per dose. Intranasal protocols use 100 mcg per dose.[6][33][9][32][22]

Frequency

Injectable protocols use 2-3 doses daily. Intranasal protocols use 2 doses daily.[6][33][9][32][22]

Timing Considerations

Common timing is morning, before a workout, or before bed, usually away from food.[6][33][9][32][22]

Cycle Length

Injectable cycles run 8-12 weeks. Intranasal cycles run about 4 weeks.[6][33][9][32][22]

What to expect

First week

Injectable GH-pulse use may first show stronger hunger, sleep changes, water retention, or shifts in training-day recovery.[6][9]

Weeks 4-8

Appetite pattern, waist, training tolerance, recovery notes, IGF-1, and fasting glucose become clearer once timing and food windows are consistent.[6][33][9]

After stopping

Appetite, water retention, and IGF-1-related markers often drift toward baseline after short-acting GH secretagogue exposure ends.[8][6][9]

Safety profile

Injectable GHRP-2 safety centers on appetite change, water retention, glucose and IGF-1 effects, ACTH/cortisol/prolactin biology, injection quality, pregnancy avoidance, active malignancy caution, and sports prohibition.[6][33][9][35][38]

Common side effects

Appetite change[6][9]
Water retention[6][33][9]

Cautions

Glucose monitoring[6][33][9][35][38]
ACTH/cortisol/prolactin effects[6][9]
Active malignancy[6][33][9][35][38]
Sports prohibited[40]

Who GHR-2 (GHRP-2) is not for

Route-specific avoid and medical-review notes:

Active or recent cancer
Avoid outside specialist-directed care because GH/IGF-1 pathway stimulation can be inappropriate in malignancy contexts.[6][33][9][35][38]
Pregnancy or breastfeeding
Avoid because reproductive and lactation safety are not established for unapproved GH secretagogue use.[6][33][9][35][38]
Acromegaly or GH excess
Do not add GH secretagogue stimulation when GH/IGF-1 excess is present or suspected.[6][33][9][35][38]

Drug & supplement interactions

Documented interactions are separated from theoretical or route-specific cautions.

Theoretical interactions

Diabetes medications
Diabetes medications can become harder to adjust when injectable GH-axis stimulation shifts glucose control; this is a theoretical GH/insulin-axis caution.[6][33][9][35][38]
Other GH-axis agents
GHRH analogs, GHRPs, or HGH can add overlapping IGF-1, water-retention, glucose, and sports-risk concerns with injectable GHRP-2; this is a stack-level safety caution.[6][33][9][35][38]

Pairing notes

Not recommended with

Somatropin: compounded GH/IGF-1 effectsInjectable

This pairing compounds GH/IGF-1 stimulation through direct growth hormone plus an upstream release signal, increasing the need to review IGF-1, glucose, fluid retention, joint symptoms, and the reason for using both.[1][38][41]

Ipamorelin: duplicate GH-release signalInjectable, Intranasal

Ipamorelin and GHRP-2 both stimulate the ghrelin/GHS receptor pathway to release growth hormone. Combining two secretagogues duplicates the same release signal without an established additive clinical benefit.[42][1][43][38]

GHRP-6: duplicate GH-release signalInjectable, Intranasal

GHRP-2 and GHRP-6 both stimulate the ghrelin/GHS receptor pathway to release growth hormone. Combining two secretagogues duplicates the same release signal without an established additive clinical benefit.[1][44][38]

Hexarelin: duplicate GH-release signalInjectable, Intranasal

GHRP-2 and Hexarelin both stimulate the ghrelin/GHS receptor pathway to release growth hormone. Combining two secretagogues duplicates the same release signal without an established additive clinical benefit.[1][45][38]

Related peptides

Ipamorelin

Regulatory status

United States

GHRP-2 has no FDA-approved injectable U.S. use as of 2026-06-21. FDA warning-letter materials also state GHRP-2 was not eligible for 503A exemptions in that context because it was not on the bulks list or an approved-drug component.[35][38]

Route	FDA drug approval	503A compounding
Injectable	Not Approved As of 2026-06-21, GHRP-2 was not FDA-approved as an injectable drug. FDA warning-letter context also separates 503A eligibility from FDA drug approval.[35][38]	Not Listed FDA warning-letter materials state that GHRP-2 did not appear on the 503A Bulks List, was not an FDA-approved drug component, and had not been nominated with adequate support for FDA to evaluate it.[38]

Injectable

FDA drug approval

Not Approved

As of 2026-06-21, GHRP-2 was not FDA-approved as an injectable drug. FDA warning-letter context also separates 503A eligibility from FDA drug approval.[35][38]

503A compounding

Not Listed

FDA warning-letter materials state that GHRP-2 did not appear on the 503A Bulks List, was not an FDA-approved drug component, and had not been nominated with adequate support for FDA to evaluate it.[38]

International

EU/Europe, UK, Canada, and Australia should be checked by local medicine and compounding rules; any non-U.S. diagnostic or research context should not be generalized to therapeutic approval.

Sports & competition

WADA's 2026 Prohibited List treats GHRPs and growth hormone secretagogues as S2-prohibited; tested athletes should treat injectable GHRP-2 use as prohibited without a valid TUE.[40]

How it works

GHRP-2 is a ghrelin/GHS receptor agonist that triggers pituitary GH release rather than acting as replacement growth hormone. Human endocrine studies show GH and IGF-1 responses, and a separate appetite study shows that ghrelin-receptor signaling can affect food intake.[6][9]

For injectable use, that broader receptor biology matters because GHRP-2 is less selective than cleaner GH-secretagogue narratives suggest. The mechanism can overlap with appetite, glucose, fluid retention, cortisol, and prolactin interpretation; it does not prove long-term body-composition, recovery, sleep, or longevity benefit in people.[6][14]

Research gaps & open questions

What the current literature has not yet settled about GHR-2 (GHRP-2):

Long-term controlled studies need to show whether GHRP-2 improves fat loss, lean mass, recovery, or sleep, and how repeated use affects blood sugar, IGF-1, cortisol, and prolactin.[6][33][9]

Direct comparisons with other growth-hormone-releasing peptides should measure real benefits and side effects, not only the size of a temporary growth-hormone pulse.[6][9]

Athletes need clearer data on detection windows and product-contamination risk because GHRP-2 is prohibited in sport.[40]

Common questions

Is GHRP-2 FDA-approved?

No. GHRP-2 has no FDA-approved injectable U.S. use, and it is not on the 503A Bulks List.[35][38]

Is GHRP-2 banned in tested sports?

Yes. WADA treats GHRPs and GH secretagogues such as GHRP-2 as S2-prohibited without a valid TUE.[40]

What makes GHRP-2 different?

GHRP-2 is generally more potent for GH release than GHRP-6 and less selective than ipamorelin, with more cortisol, prolactin, and appetite concern.[6][9]

Myths & misconceptions

Myth

GHRP-2 is undetectable because it clears quickly.

Reality

Short plasma exposure does not mean no sports-detection risk; WADA class rules and urine metabolite methods matter.[40][16]

Myth

GHRP-2 is safe because it stimulates natural GH.

Reality

Stimulating endogenous GH is still pharmacologic and can affect appetite, glucose, water retention, IGF-1, cortisol, or prolactin depending on the compound.[6][33][9]

History & discovery

GHRP-2, also known as pralmorelin, belongs to the synthetic secretagogue lineage that helped separate ghrelin/GHS-receptor pharmacology from direct growth hormone replacement.[8][6][9]

Phase I and older-adult studies used GHRP-2 to probe GH and IGF-1 responses, often alongside GHRH, before wellness-market protocols became common.[6][33][9]

Human obesity research showed GHRP-2 could stimulate food intake, helping connect the peptide with ghrelin-like appetite signaling as well as GH release.[9]

Urine detection work and WADA class rules made anti-doping status part of the modern history, while U.S. use remains outside FDA-approved injectable products.[40][16][35][38]

Published research40 studies

[1]

Growth hormone-releasing peptide-2 infusion synchronizes growth hormone, thyrotrophin and prolactin release in prolonged critical illness.

European journal of endocrinology, 1999 Jan. human clinical.

[2]

Preservation of growth hormone secretion in response to growth hormone-releasing peptide-2 during prednisone therapy.

Metabolism: clinical and experimental, 1999 May. human clinical.

[3]

The effects of growth hormone-releasing peptide-2 (GHRP-2) on the release of growth hormone and growth performance in swine.

Domestic animal endocrinology, 2000 Apr. animal.

[4]

Effects of the administration of growth hormone-releasing peptide-2 (GHRP-2) orally by gavage and in feed on growth hormone release in swine.

Domestic animal endocrinology, 2001 Jan. animal.

[5]

Interactive regulation of postmenopausal growth hormone insulin-like growth factor axis by estrogen and growth hormone-releasing peptide-2.

Endocrine, 2001 Feb. review.

[6]

Growth hormone/insulin-like growth factor-1 response to acute and chronic growth hormone-releasing peptide-2, growth hormone-releasing hormone 1-44NH2 and in combination in older men and women with decreased growth hormone secretion.

Endocrine, 2001 Feb. human clinical.

[7]

Chicken ghrelin and growth hormone-releasing peptide-2 inhibit food intake of neonatal chicks.

European journal of pharmacology, 2002 Oct 18. animal.

[8]

Pralmorelin: GHRP 2, GPA 748, growth hormone-releasing peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102LN.

Drugs in R&D, 2004. review.

[9]

Obese subjects respond to the stimulatory effect of the ghrelin agonist growth hormone-releasing peptide-2 on food intake.

Obesity (Silver Spring, Md.), 2006 Jun. human clinical.

[10]

Diagnostic usefulness of the growth hormone-releasing peptide-2 test as a substitute for the insulin tolerance test in hypopituitarism.

Endocrine journal, 2008 Aug. review.

[11]

The effect of growth hormone releasing peptide-2 on upper gastrointestinal contractile activity and food intake in conscious dogs.

Journal of gastroenterology, 2009. animal.

[12]

Growth hormone-releasing peptide-2 stimulates secretion and synthesis of adrenocorticotropic hormone in mouse pituitary.

Regulatory peptides, 2009 Nov 27. animal.

[13]

Exaggerated response of adrenocorticotropic hormone to growth hormone-releasing peptide-2 test in Cushing's disease. Case report.

Neurologia medico-chirurgica, 2009 Aug. review.

[14]

Comparison of pituitary-adrenal responsiveness between insulin tolerance test and growth hormone-releasing peptide-2 test: a pilot study.

Peptides, 2010 Apr. review.

[15]

Concordant and discordant adrenocorticotropin (ACTH) responses induced by growth hormone-releasing peptide-2 (GHRP-2), corticotropin-releasing hormone (CRH) and insulin-induced hypoglycemia in patients with hypothalamopituitary disorders: evidence for direct ACTH releasing activity of GHRP-2.

Endocrine journal, 2010. review.

[16]

Determination of growth hormone secretagogue pralmorelin (GHRP-2) and its metabolite in human urine by liquid chromatography/electrospray ionization tandem mass spectrometry.

Rapid communications in mass spectrometry : RCM, 2010 Jul 30. review.

[17]

Growth hormone releasing peptide-2, a ghrelin agonist, attenuates lipopolysaccharide-induced acute lung injury in rats.

The Tohoku journal of experimental medicine, 2010 Sep. animal.

[18]

Identification of the growth-hormone-releasing peptide-2 (GHRP-2) in a nutritional supplement.

Drug testing and analysis, 2010 Mar. review.

[19]

Influence of intravenous administration of growth hormone releasing peptide-2 (GHRP-2) on detection of growth hormone doping: growth hormone isoform profiles in Japanese male subjects.

Drug testing and analysis, 2010 Nov-Dec. review.

[20]

Growth hormone response to growth hormone-releasing peptide-2 in growth hormone-deficient little mice.

Clinics (Sao Paulo, Brazil), 2012. animal.

[21]

Synthesis of Mono-PEGylated Growth Hormone Releasing Peptide-2 and Investigation of its Biological Activity.

AAPS PharmSciTech, 2015 Oct. review.

[22]

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 Sep. review.

[23]

Investigation of the clinical significance of the growth hormone-releasing peptide-2 test for the diagnosis of secondary adrenal failure.

Endocrine journal, 2016 Jun 30. human clinical.

[24]

Growth Hormone Releasing Peptide-2 Attenuation of Protein Kinase C-Induced Inflammation in Human Ovarian Granulosa Cells.

International journal of molecular sciences, 2016 Aug 19. in vitro.

[25]

Evaluation of growth hormone-releasing peptide-2 for diagnosis of thyrotropin-producing pituitary adenomas.

Endocrine journal, 2018 Oct 29. review.

[26]

Clinical Usefulness of the Growth Hormone-Releasing Peptide-2 Test for Hypothalamic-Pituitary Disorder.

Journal of the Endocrine Society, 2022 Aug 1. review.

[27]

Assessment of anterior pituitary reserve capacity based on growth hormone response to growth hormone-releasing peptide-2 test in the elderly.

Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society, 2023 Aug. review.

[28]

Growth Hormone-Releasing Peptide 2 May Be Associated With Decreased M1 Macrophage Production and Increased Histologic and Biomechanical Tendon-Bone Healing Properties in a Rat Rotator Cuff Tear Model.

Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association, 2025 Jul. animal.

[29]

Diagnostic studies with intravenous and intranasal growth hormone-releasing peptide-2 in children of short stature.

The Journal of clinical endocrinology and metabolism, 1995 Oct. human clinical.

[30]

Effects of growth hormone-releasing peptide-2 (GHRP-2) on membrane Ca2+ permeability in cultured ovine somatotrophs.

Journal of neuroendocrinology, 1995 Mar. in vitro.

[31]

Characteristics of growth hormone secretion responsiveness to growth hormone-releasing peptide-2 (GHRP-2 or KP102) in calves.

Endocrine journal, 1996 Jun. animal.

[32]

Treatment effects of intranasal growth hormone releasing peptide-2 in children with short stature.

The Journal of endocrinology, 1997 Oct. human clinical.

[33]

Pharmacokinetics and pharmacodynamics of growth hormone-releasing peptide-2: a phase I study in children.

The Journal of clinical endocrinology and metabolism, 1998 Apr. human clinical.

[34]

Effect of growth hormone-releasing peptide-2 (GHRP-2) and GH-releasing hormone (GHRH) on the the cAMP levels and GH release from cultured acromegalic tumours.

Journal of neuroendocrinology, 1998 Jun. in vitro.

[35]

Drugs@FDA/openFDA query for GHRP-2

U.S. Food and Drug Administration / openFDA. database query.

[36]

Drugs@FDA/openFDA query for Pralmorelin

U.S. Food and Drug Administration / openFDA. database query.

[37]

Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act

U.S. Food and Drug Administration, 2026-05-14. regulatory.

[38]

United Pharmacy MARCS-CMS 553916 - February 11, 2019

U.S. Food and Drug Administration, 2019-02-11. regulatory.

[39]

Compounding and the FDA: Questions and Answers

U.S. Food and Drug Administration. official guidance.

[40]

The 2026 List of Prohibited Substances and Methods

World Anti-Doping Agency, 2026. regulatory.