GHRP-2 10 mg

GHRP-2 10 mg research-grade lyophilized peptide powder in a glass vial. GHRP-2 (Growth Hormone Releasing Peptide 2, Pralmorelin) is a synthetic hexapeptide growth hormone secretagogue studied in experimental models of ghrelin receptor (GHS-R) activation, pituitary hormone regulation and metabolic signaling pathways.

Research Overview

GHRP-2 is a synthetic growth hormone secretagogue peptide that acts as an agonist of the ghrelin/GHS-R receptor in experimental models. It is used in vitro and in vivo to study pulsatile growth hormone release, pituitary and hypothalamic signaling networks, and interactions with metabolic and stress-related pathways, without implying any therapeutic use.

Primary Research Areas

• Ghrelin receptor (GHS-R) activation: Models investigating GHRP-2 as a tool agonist of the ghrelin receptor and downstream signaling cascades in pituitary and hypothalamic cells [8].
• Growth hormone secretion dynamics: In vitro and in vivo systems examining pulsatile GH release, feedback regulation and interactions with other pituitary hormones [2,3,6].
• Metabolic & endocrine research models: Studies exploring how GHRP-2–induced GH/ghrelin signaling affects energy balance, body-composition pathways and cellular growth mechanisms in controlled laboratory settings [5,6].
• Cortisol and prolactin rise too: in six healthy young adults given GHRP-2 into a vein, prolactin, ACTH and cortisol all went up alongside growth hormone, with the cortisol push about as strong as a dose of CRH. In critically ill adults a bolus raised cortisol by 35 per cent [1,2].
• It stops working within days: nine healthy young men injected 100 micrograms daily for five days: peak growth hormone fell from 83 to 51 micrograms per litre by day five, and IGF-1 never rose at all. The body adapts fast, so daily use loses its effect [3].
• Bigger effect on an empty stomach: ten healthy men got 100 micrograms into a vein fasted and fed; growth hormone, ACTH and prolactin peaks were all higher when fasted. Blood pressure, blood concentration and the water-retaining hormone vasopressin did not change, so timing relative to food matters [4].
• Swollen joints in arthritic rats: rats with adjuvant arthritis were injected with GHRP-2 at 100 micrograms per kilo daily for eight days; their arthritis score dropped from 13.4 to 10.4, paws were less swollen, and blood interleukin-6 fell. It is one rat study [5].
• Wasting in critical illness: twenty-six critically ill adults, who lose muscle while keeping fat, were infused with GHRP-2 for 21 hours; IGF-1 rose 61 per cent within a day, without moving their already high cortisol. This is short-term blood chemistry, not recovery or survival [6].
• Appetite needs an intact vagus nerve: into a vein, GHRP-2 made conscious dogs eat more, but it did nothing in dogs whose vagus nerve had been cut. It also briefly switched off stomach and gut contractions for two to three minutes after a meal [7].

References

1. 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. Comparison with the effects of GHRH, TRH and hCRH. Peptides. 1997;18(6):885-91. PMID 9285939. doi:10.1016/s0196-9781(97)00016-8
2. Van den Berghe G, de Zegher F, Bowers CY, et al. Pituitary responsiveness to GH-releasing hormone, GH-releasing peptide-2 and thyrotrophin-releasing hormone in critical illness. Clin Endocrinol (Oxf). 1996;45(3):341-51. PMID 8949573. doi:10.1046/j.1365-2265.1996.00805.x
3. Nijland EA, Strasburger CJ, Popp-Snijders C, et al. 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. Eur J Endocrinol. 1998;139(4):395-401. PMID 9820615. doi:10.1530/eje.0.1390395
4. Kamoi K, Minagawa S, Kimura K, et al. GH-releasing peptide-2 does not stimulate arginine vasopressin secretion in healthy men. Endocr J. 2010;57(2):175-80. PMID 19907099. doi:10.1507/endocrj.k09e-215
5. Granado M, Priego T, Martín AI, et al. Anti-inflammatory effect of the ghrelin agonist growth hormone-releasing peptide-2 (GHRP-2) in arthritic rats. Am J Physiol Endocrinol Metab. 2005;288(3):E486-92. PMID 15507538. doi:10.1152/ajpendo.00196.2004
6. Van den Berghe G, de Zegher F, Veldhuis JD, et al. The somatotropic axis in critical illness: effect of continuous growth hormone (GH)-releasing hormone and GH-releasing peptide-2 infusion. J Clin Endocrinol Metab. 1997;82(2):590-9. PMID 9024260. doi:10.1210/jcem.82.2.3736
7. Kudoh K, Shibata C, Funayama Y, et al. The effect of growth hormone releasing peptide-2 on upper gastrointestinal contractile activity and food intake in conscious dogs. J Gastroenterol. 2009;44(4):297-304. PMID 19271111. doi:10.1007/s00535-009-0025-y
8. Kageyama K, Kushibiki M, Hanada K, et al. Growth hormone-releasing peptide-2 stimulates secretion and synthesis of adrenocorticotropic hormone in mouse pituitary. Regul Pept. 2009;158(1-3):116-20. PMID 19682503. doi:10.1016/j.regpep.2009.07.018