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Research information only. Not medical advice. 18+ only. Not FDA-approved for human therapeutic use.

GHRP-2

Also known as: Pralmorelin, GPA-748, KP-102 D, KP-102 LN, KP-102D, KP-102LN, Growth hormone-releasing peptide 2, D-Ala-D-(β-naphthyl)-Ala-Ala-Trp-D-Phe-Lys-NH2

Growth Hormone Secretagogue (GHS) / Synthetic Growth Hormone-Releasing Peptide (GHRP) / Ghrelin Receptor Agonist

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What it is

GHRP-2 is a synthetic hexapeptide (D-Ala-D-β-naphthylAla-Ala-Trp-D-Phe-Lys-NH2) that acts as a potent agonist at the growth hormone secretagogue receptor (GHS-R1a / ghrelin receptor), a G-protein-coupled receptor distinct from the GHRH receptor (PMID 9798733, PMID 51). It stimulates GH secretion from pituitary somatotrophs through a mechanism involving protein kinase C (PKC) and intracellular calcium signalling, distinct from the cAMP/PKA pathway used by GHRH. GHRP-2 acts at both pituitary and hypothalamic levels, and its GH-releasing effect is synergistic with that of GHRH (PMID 9186261, PMID 9465289). Beyond GH release, GHRP-2 also stimulates ACTH/cortisol and prolactin secretion (PMID 9285939, PMID 45), and does not stimulate arginine vasopressin (AVP) secretion in healthy men. It acts as a synthetic mimic of ghrelin, the endogenous GHS-R1a ligand. GHRP-2 has also been shown to bind CD36, a scavenger receptor for oxidized LDL, and to exert antioxidant effects in vascular tissue independent of GH. In granulosa cells, GHRP-2 attenuates PKC-mediated inflammation via inhibition of p38, JNK, and NF-κB pathways.

Class: Growth Hormone Secretagogue (GHS) / Synthetic Growth Hormone-Releasing Peptide (GHRP) / Ghrelin Receptor Agonist

What it's studied for

  • Diagnostic test for adult growth hormone deficiency (AGHD) Human observational
    • 100 µg GHRP-2 IV in 77 healthy subjects and 58 GHD patients; peak GH cut-off of 15 µg/L (9 µg/L with WHO 98/574 standard) distinguished GHD from controls with high reliability. Test showed favourable reproducibility and mild influence of age and adiposity. PMID 17609397 Chihara K et al. European Journal of Endocrinology (2007)
    • GHRP-2 test compared to ITT and arginine test in 71 Japanese adults with pituitary tumours. GHRP-2 sensitivity 81.3% and specificity 94.5% for severe AGHD vs ITT. Median peak GH 28.88 µg/L with GHRP-2 vs 9.38 µg/L with ITT. PMID 23079545 Kinoshita Y et al. Endocrine Journal (2013)
    • Review: GHRP-2 test recommended in Japan as convenient and safe GH stimulating test; cut-off for severe AGHD is peak GH ≤9 ng/mL (9 µg/L). PMID 25070016 Fukuda I et al. Neurologia medico-chirurgica (2014)
    • Preoperative GHRP-2 test peak GH values in NFPA patients reflected severity of hypopituitarism and predicted postoperative recovery of GH secretion. Cut-off for severe AGHD is ≤9 ng/mL. PMID 31776295 Soga A et al. Endocrine Journal (2020)
    • In 65 elderly patients (≥65 yr) with non-functioning pituitary NETs, GH response to GHRP-2 test correlated significantly with adrenocortical function; optimal cut-off for peak GH 8.08 ng/mL (sensitivity 85.2%, specificity 86.8%) for predicting adrenocortical insufficiency. PMID 37295337 Teramoto S et al. Growth Hormone & IGF Research (2023)
  • Diagnostic test for GH deficiency in children Human observational
    • 2 µg/kg GHRP-2 IV in 56 children with growth disorders; peak GH significantly lower in GHD (median 3.39 µg/L) vs non-GHD (25.10 µg/L). Cross-specificity point at 15 µg/L. Test was safe and required ≤1 hour. PMID 20662346 Asakura Y et al. Journal of Pediatric Endocrinology & Metabolism (2010)
    • In 23 adolescents, GH response to GHRP-2T was robustly high in idiopathic GHD and short stature groups (medians 88.9 and 90.1 ng/mL respectively) but low in organic/genetic GHD (median 3.4 ng/mL). Authors suggest current cut-off may miss some GHD patients in adolescents. PMID 38958228 Onuki T et al. Journal of Pediatric Endocrinology & Metabolism (2024)
  • Diagnosis of secondary adrenal failure / HPA axis assessment Human observational
    • GHRP-2 test in 47 patients: cut-off of 11.6 µg/dL for peak cortisol predicted secondary hypoadrenalism with 88.9% specificity and 89.7% sensitivity. ACTH/cortisol responses to GHRP-2 did not correlate with CRH test, suggesting direct pituitary ACTH stimulation. PMID 27020037 Arimura H et al. Endocrine Journal (2016)
    • In 6 patients with hypothalamo-pituitary disorders who failed ITT, significant ACTH release was observed during GHRP-2 test, suggesting GHRP-2 may directly stimulate ACTH secretion. PMID 20431231 Kimura T et al. Endocrine Journal (2010)
  • Diagnosis of GH secretory status in pituitary tumor patients / overweight subjects Human observational
    • In 104 patients with NFPA or Rathke's cyst, 43% had severe GHD by GHRP-2 test. BMI, free thyroxine, and tumor height significantly predicted peak GH response. Overweight (OR 3.86) was significantly associated with severe GHD. PMID 35452483 Seki Y & Ichihara A. PLoS One (2022)
    • GH secretion (GHRP-2 load test) negatively correlated with BMI (r=-0.59), visceral adipose tissue, and subcutaneous adipose tissue in 28 obese subjects. Response markedly improved after laparoscopic sleeve gastrectomy. PMID 28623445 Ohara E et al. Obesity Surgery (2017)
  • Treatment of prolonged critical illness / hyposomatotropism in ICU patients Human RCT
    • Continuous GHRP-2 infusion (1 µg/kg/h) in 26 critically ill adults caused 4–6-fold increase in mean GH concentration and 61% rise in serum IGF-I within 24 h. GHRH + GHRP-2 combination caused further 2-fold increase in GH over GHRP-2 alone. PMID 9024260 Van den Berghe G et al. Journal of Clinical Endocrinology & Metabolism (1997)
    • RCT in 33 critically ill men: GHRP-2 alone (1 µg/kg/h continuous) reactivated GH secretion and normalized IGF-I. Combined GHRP-2+TRH+GnRH reactivated GH, TSH, and LH axes with beneficial metabolic effects; ureagenesis reduced only with TRH co-treatment. PMID 12030918 Van den Berghe G et al. Clinical Endocrinology (2002)
    • Continuous GHRP-2 infusion (1 µg/kg/h) in critically ill patients synchronized serum profiles of GH, TSH and PRL; GHRH or TRH alone did not produce this synchronization. PMID 10037246 Van den Berghe G et al. European Journal of Endocrinology (1999)
  • Stimulation of food intake / appetite (orexigenic effect) Human RCT
    • Subcutaneous infusion of GHRP-2 (1 µg/kg/h for 270 min) in 7 lean healthy males increased ad libitum food intake by 35.9 ± 10.9% vs saline. All subjects increased intake. GH AUC significantly elevated during GHRP-2 infusion. PMID 15699539 Laferrère B et al. Journal of Clinical Endocrinology & Metabolism (2005)
  • Treatment of short stature / GH deficiency in children (intranasal or oral administration) Human observational
    • 15 children with short stature received intranasal GHRP-2 (5–15 µg/kg, 2–3x/day) for up to 24 months; height velocity increased from 3.7 to 6.1 cm/year at 6 months. GH-binding protein concentrations rose significantly. Well tolerated. PMID 9390009 Pihoker C et al. The Journal of Endocrinology (1997)
    • Oral GHRP-2 (900 µg/kg b.i.d.) for 12 months in 10 prepubertal GHD children: 7/10 reported increased appetite in first 6 months; BMI SDS trended upward but did not reach statistical significance. PMID 14513874 Mericq V et al. Journal of Pediatric Endocrinology & Metabolism (2003)
  • Modulation of GH secretory dynamics in healthy adults (mechanistic/pharmacodynamic studies) Human RCT
    • Prospective RCT in 26 older men: continuous GHRP-2 infusion combined with GHRH pulses; pulsatile GH correlated positively with testosterone and negatively with BMI. Mean GH under GHRP-2 predicted jointly by estradiol (positively) and BMI (negatively). PMID 23101768 Norman C et al. American Journal of Physiology (2013)
    • In 10 healthy men, SSTR-2/-5 agonist octreotide (1 µg/kg SC) suppressed GHRP-2 (1 µg/kg IV)-stimulated GH secretory burst mass, frequency, and irregularity, demonstrating interactive control of GH secretion. PMID 15356066 Iranmanesh A et al. Journal of Clinical Endocrinology & Metabolism (2004)
  • Vascular antioxidant effects (animal/in vitro) Animal studies only
    • GHRP-2 (20 µg twice daily SC) in ApoE-/- mice for 12 weeks: increased circulating IGF-I, decreased interferon-gamma by 66%, decreased aortic superoxide and 12/15-lipoxygenase expression; did not reduce atherosclerotic plaque area. PMID 19819949 Titterington JS et al. Endocrinology (2009)
  • Anti-inflammatory effects in ovarian granulosa cells (in vitro) In vitro only
    • GHRP-2 attenuated PKC activator (PDD)-induced COX-2 and IL-8 expression in KGN human granulosa cells, reduced PGE2 and IL-8 secretion, and inhibited p38, JNK, and NF-κB signalling pathways. PMID 27548147 Chao YN et al. International Journal of Molecular Sciences (2016)
  • Growth performance and muscle protein deposition in animals with growth retardation Animal studies only
    • GHRP-2 injection in growth-retarded yaks significantly enhanced average daily gain, myofiber diameter and area, serum GH and IGF-1 levels, and upregulated GHR, IGF-1R, and protein synthesis pathway (PI3K/AKT/mTOR) mRNA in liver and skeletal muscle. PMID 26894743 Hu R et al. PLoS One (2016)
  • Cachexia / wasting syndrome treatment (proposed) Mixed
    • Narrative review identifies GHRP-2 as a potential pharmacological option in cachexia treatment; notes that evidence-based recommendations for its use are not yet available. PMID 35758863 Celichowska M et al. Journal of Pain & Palliative Care Pharmacotherapy (2022)
  • Diagnostic tool for TSH-producing pituitary adenomas Human observational
    • In 5 patients with TSH-producing adenomas, 2 (40%) showed >50% increase in TSH after GHRP-2 test. GHRP-2 fails to induce TSH in normal subjects; proposed as potential additional diagnostic tool alongside TRH test. PMID 29973439 Kageyama K et al. Endocrine Journal (2018)

Community-reported dosing

RouteDoseFrequency / DurationPopulation / contextSource tier
Intravenous (IV) bolus100 µg (single dose)Single administration; blood sampled over 2 hhumanResearch PMID 17609397
Intravenous (IV)2 µg/kgSingle administration; blood sampled over 1 hhumanResearch PMID 20662346
Subcutaneous infusion1 µg/kg/h270-minute infusionhumanResearch PMID 15699539
Intravenous (IV) continuous infusion1 µg/kg/h (continuous infusion)5 dayshumanResearch PMID 12030918
Intravenous (IV) continuous infusion1 µg/kg/h (preceded by 1 µg/kg bolus)21-hour infusion over 2 consecutive nightshumanResearch PMID 9024260
Intravenous (IV) continuous infusion1 µg/kg/h21-hour continuous infusionhumanResearch PMID 10037246
Intranasal (therapeutic); Intravenous (bolus for acute testing)5–15 µg/kg per dose (acute IV bolus 1 µg/kg; intranasal 5–20 µg/kg for GH response testing; therapeutic intranasal 5–15 µg/kg)6–24 months (therapeutic intranasal phase); initial 3 months twice daily then 3 times dailyhumanResearch PMID 9390009
Oral900 µg/kg b.i.d. (orally)12 monthshumanResearch PMID 14513874
Intravenous (IV) over 1 min1 µg/kgSingle dose; blood sampled over 2 hhumanResearch PMID 9543135
Intravenous (IV) continuous infusion1 µg/kg/h24-hour continuous infusionhumanResearch PMID 10946861
Intravenous (IV) bolus1 µg/kgSingle bolus; sessions repeated on separate dayshumanResearch PMID 15356066
Intravenous (IV) bolus100 µgSingle intravenous bolus; measurements over 60 minhumanResearch PMID 19907099
Intravenous (IV) bolus1 µg/kg and 2 µg/kgSingle bolushumanResearch PMID 9285939
Intravenous (IV) bolus2.0 µg/kgSingle bolushumanResearch PMID 10195374
Intravenous (IV) bolus1 µg/kg bolusSingle bolus per sessionhumanResearch PMID 11004017
Intravenous (IV)100 µg (single dose)Single administration; detected in DBS up to 4 h post-injectionhumanResearch PMID 33197153
Intravenous (IV)100 µgSingle intravenous administrationhumanResearch PMID 25249726
Not specified for GH replacement contextInitial low dose 3 µg/kg body weight/day (GH replacement therapy reference, not GHRP-2 treatment dose)Ongoing with dose titrationhumanResearch PMID 25070016
Subcutaneous (SC)20 µg twice daily12 weeksanimalResearch PMID 19819949
Injection (route not further specified in abstract)Not explicitly stated (GHRP-2 injection group vs control in yaks)Study period not specified in abstractanimalResearch PMID 26894743
Intravenous and subcutaneousNot explicitly stated per kg; chronic administration studied7–30 dayshumanResearch PMID 8887169
subcutaneous injection100 mcg3x daily (upon waking, post-workout, before bed)male bodybuilders and performance-focused biohackers seeking GH pulse amplification[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection200 mcg3x daily (upon waking, post-workout, before bed)experienced male bodybuilders and biohackers tolerant to GHRP side effects[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection300 mcg3x daily (upon waking, post-workout, before bed)advanced bodybuilders pushing for maximum GH output per pulse[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection100 mcg2x daily (upon waking, before bed)biohackers and anti-aging focused adults seeking moderate GH support with minimal side effects[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection100 mcgonce daily, 30 minutes before bedgeneral biohackers and older adults prioritizing sleep-related GH pulse and recovery[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection100 mcg3x daily, co-injected with Mod GRF 1-29 (CJC-1295 no-DAC) 100 mcgintermediate-to-advanced biohackers and bodybuilders using GHRP+GHRH stacks[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection200 mcg3x daily, co-injected with Mod GRF 1-29 (CJC-1295 no-DAC) 100 mcgexperienced bodybuilders running aggressive GHRP+GHRH stacks for maximum GH output[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection100 mcgonce daily, 30 minutes pre-workout or post-workout (fasted state)performance-oriented athletes and bodybuilders using GHRP-2 for intra-cycle recovery support[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection50 mcg2x daily (upon waking, before bed)beginners, females, or older adults starting GHRP-2 for the first time to assess tolerance[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection100 mcg3x daily, co-injected with CJC-1295 with DAC 2 mg (dosed 1-2x per week separately)biohackers and bodybuilders using a long-acting GHRH alongside GHRP-2 for convenience[S] Claude Sonnet 4.6 — synthesized from aggregate training data
subcutaneous injection100 mcg3x daily, co-injected with Ipamorelin 100 mcg as a replacement or transition protocolbiohackers comparing or cycling between GHRPs, or layering for additive pulse effect[S] Claude Sonnet 4.6 — synthesized from aggregate training data

Tier key: Research = PMID-cited study · [C] = scraped community source · [S] = model-synthesized from aggregate community reports (softer evidence). How we source.

References

  1. [1] PMID 17609397 — 100 µg GHRP-2 IV in 77 healthy subjects and 58 GHD patients; peak GH cut-off of 15 µg/L (9 µg/L with WHO 98/574 standard) distinguished GHD from controls with h
  2. [2] PMID 23079545 — GHRP-2 test compared to ITT and arginine test in 71 Japanese adults with pituitary tumours. GHRP-2 sensitivity 81.3% and specificity 94.5% for severe AGHD vs IT
  3. [3] PMID 25070016 — Review: GHRP-2 test recommended in Japan as convenient and safe GH stimulating test; cut-off for severe AGHD is peak GH ≤9 ng/mL (9 µg/L).
  4. [4] PMID 31776295 — Preoperative GHRP-2 test peak GH values in NFPA patients reflected severity of hypopituitarism and predicted postoperative recovery of GH secretion. Cut-off for
  5. [5] PMID 37295337 — In 65 elderly patients (≥65 yr) with non-functioning pituitary NETs, GH response to GHRP-2 test correlated significantly with adrenocortical function; optimal c
  6. [6] PMID 20662346 — 2 µg/kg GHRP-2 IV in 56 children with growth disorders; peak GH significantly lower in GHD (median 3.39 µg/L) vs non-GHD (25.10 µg/L). Cross-specificity point a
  7. [7] PMID 38958228 — In 23 adolescents, GH response to GHRP-2T was robustly high in idiopathic GHD and short stature groups (medians 88.9 and 90.1 ng/mL respectively) but low in org
  8. [8] PMID 27020037 — GHRP-2 test in 47 patients: cut-off of 11.6 µg/dL for peak cortisol predicted secondary hypoadrenalism with 88.9% specificity and 89.7% sensitivity. ACTH/cortis
  9. [9] PMID 20431231 — In 6 patients with hypothalamo-pituitary disorders who failed ITT, significant ACTH release was observed during GHRP-2 test, suggesting GHRP-2 may directly stim
  10. [10] PMID 35452483 — In 104 patients with NFPA or Rathke's cyst, 43% had severe GHD by GHRP-2 test. BMI, free thyroxine, and tumor height significantly predicted peak GH response. O
  11. [11] PMID 28623445 — GH secretion (GHRP-2 load test) negatively correlated with BMI (r=-0.59), visceral adipose tissue, and subcutaneous adipose tissue in 28 obese subjects. Respons
  12. [12] PMID 9024260 — Continuous GHRP-2 infusion (1 µg/kg/h) in 26 critically ill adults caused 4–6-fold increase in mean GH concentration and 61% rise in serum IGF-I within 24 h. GH
  13. [13] PMID 12030918 — RCT in 33 critically ill men: GHRP-2 alone (1 µg/kg/h continuous) reactivated GH secretion and normalized IGF-I. Combined GHRP-2+TRH+GnRH reactivated GH, TSH, a
  14. [14] PMID 10037246 — Continuous GHRP-2 infusion (1 µg/kg/h) in critically ill patients synchronized serum profiles of GH, TSH and PRL; GHRH or TRH alone did not produce this synchro
  15. [15] PMID 15699539 — Subcutaneous infusion of GHRP-2 (1 µg/kg/h for 270 min) in 7 lean healthy males increased ad libitum food intake by 35.9 ± 10.9% vs saline. All subjects increas
  16. [16] PMID 9390009 — 15 children with short stature received intranasal GHRP-2 (5–15 µg/kg, 2–3x/day) for up to 24 months; height velocity increased from 3.7 to 6.1 cm/year at 6 mon
  17. [17] PMID 14513874 — Oral GHRP-2 (900 µg/kg b.i.d.) for 12 months in 10 prepubertal GHD children: 7/10 reported increased appetite in first 6 months; BMI SDS trended upward but did
  18. [18] PMID 23101768 — Prospective RCT in 26 older men: continuous GHRP-2 infusion combined with GHRH pulses; pulsatile GH correlated positively with testosterone and negatively with
  19. [19] PMID 15356066 — In 10 healthy men, SSTR-2/-5 agonist octreotide (1 µg/kg SC) suppressed GHRP-2 (1 µg/kg IV)-stimulated GH secretory burst mass, frequency, and irregularity, dem
  20. [20] PMID 19819949 — GHRP-2 (20 µg twice daily SC) in ApoE-/- mice for 12 weeks: increased circulating IGF-I, decreased interferon-gamma by 66%, decreased aortic superoxide and 12/1
  21. [21] PMID 27548147 — GHRP-2 attenuated PKC activator (PDD)-induced COX-2 and IL-8 expression in KGN human granulosa cells, reduced PGE2 and IL-8 secretion, and inhibited p38, JNK, a
  22. [22] PMID 26894743 — GHRP-2 injection in growth-retarded yaks significantly enhanced average daily gain, myofiber diameter and area, serum GH and IGF-1 levels, and upregulated GHR,
  23. [23] PMID 35758863 — Narrative review identifies GHRP-2 as a potential pharmacological option in cachexia treatment; notes that evidence-based recommendations for its use are not ye
  24. [24] PMID 29973439 — In 5 patients with TSH-producing adenomas, 2 (40%) showed >50% increase in TSH after GHRP-2 test. GHRP-2 fails to induce TSH in normal subjects; proposed as pot
  25. [25] PMID 9543135 — 1 µg/kg Intravenous (IV) over 1 min (human)
  26. [26] PMID 10946861 — 1 µg/kg/h Intravenous (IV) continuous infusion (human)
  27. [27] PMID 19907099 — 100 µg Intravenous (IV) bolus (human)
  28. [28] PMID 9285939 — 1 µg/kg and 2 µg/kg Intravenous (IV) bolus (human)
  29. [29] PMID 10195374 — 2.0 µg/kg Intravenous (IV) bolus (human)
  30. [30] PMID 11004017 — 1 µg/kg bolus Intravenous (IV) bolus (human)
  31. [31] PMID 33197153 — 100 µg (single dose) Intravenous (IV) (human)
  32. [32] PMID 25249726 — 100 µg Intravenous (IV) (human)
  33. [33] PMID 8887169 — Not explicitly stated per kg; chronic administration studied Intravenous and subcutaneous (human)
  34. [34] PMID 9798733 — in-prose reference
  35. [35] PMID 51 — in-prose reference
  36. [36] PMID 9688350 — in-prose reference
  37. [37] PMID 9186261 — in-prose reference
  38. [38] PMID 9465289 — in-prose reference
  39. [39] PMID 45 — in-prose reference
  40. [40] PMID 25869809 — in-prose reference
  41. [41] PMID 8950613 — in-prose reference
  42. [42] PMID 28400207 — in-prose reference
  43. [43] PMID 42395176 — in-prose reference
  44. [44] PMID 30051972 — in-prose reference
  45. [45] PMID 12938517 — in-prose reference
  46. [46] PMID 31758732 — in-prose reference
  47. [47] PMID 20552695 — in-prose reference
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