GHRP-2 (5mg / 10mg)

Description

GHRP-2 Peptide: Growth Hormone Secretagogue for Appetite and GH Secretion

GHRP-2 is a synthetic pentapeptide (five amino acids) designed to mimic the activity of the natural hormone ghrelin. While it does not have neurotransmitter-like properties, GHRP-2 effectively activates ghrelin receptors, known as growth hormone secretagogue receptors (GHS-Rs), primarily located in the pituitary gland. By stimulating these receptors, GHRP-2 triggers the secretion of growth hormone (GH), supporting various physiological functions.

Mechanism of Action

GHRP-2’s main action involves binding to GHS-Rs in the hypothalamus, pituitary, and other tissues. Upon binding, GHRP-2 induces intracellular signaling through G-proteins, specifically activating Gαq/11. This leads to the activation of phospholipase C (PLC), which produces secondary signaling molecules like IP3 (inositol trisphosphate) and DAG (diacylglycerol). IP3 triggers the release of calcium ions, while DAG activates protein kinase C (PKC), both of which contribute to enhanced growth hormone release. Additionally, GHRP-2 may increase cyclic AMP (cAMP) levels, further amplifying the growth hormone secretion cascade. You may also be interested in our related research peptides, including Tripeptide, Sermorelin Peptide, Hexarelin, Melanotan 1, Oxytocin Peptide, Snap 8 Peptide, Pinealon, Kisspeptin 10 mg, VIP Peptide, and ARA 290 Peptide.

However, after activation, GHRP-2 receptors experience desensitization, which reduces receptor sensitivity for up to four hours.

GHRP-2 and Appetite Regulation

In addition to stimulating growth hormone secretion, GHRP-2 influences hunger and appetite regulation. By activating GHS-Rs in the brain, it promotes the production of hunger-inducing neuropeptides such as Neuropeptide Y (NPY) and Agouti-related peptide (AgRP), which help control food intake and energy balance. At the same time, GHRP-2 inhibits melanocyte-stimulating hormone (α-MSH), a hormone that reduces appetite, leading to an increase in hunger and potentially encouraging higher food consumption.

Furthermore, GHRP-2 may interact with the mesolimbic reward system, a neural pathway that regulates food cravings. By activating GHSR-1a receptors, GHRP-2 might enhance the reward-driven desire for food, influencing feeding behavior through the cAMP signaling pathway.

Chemical Makeup

Molecular Formula: C₄₅H₅₅N₉O₆
Molecular Weight: 817.97 g/mol
Other Known Titles: pralmorelin

Research and Clinical Studies on GHRP-2 Peptide

GHRP-2 Peptide and Growth Hormone Synthesis

A study conducted to evaluate the effects of synthetic GHRPs, including GHRP-2, on growth hormone (GH) secretion showed that GHRP-2 significantly increased GH levels, surpassing the physiological increase seen with native growth hormone-releasing hormone (GHRH). In comparison to other synthetic GHRPs like Hexarelin, GHRP-2 also caused an increase in ACTH and cortisol levels. Further studies demonstrated that GHRP-2 induced up to a 181-fold increase in GH production and a 47-fold increase in pulsatile GH secretion. Additionally, prolonged exposure to GHRP-2 resulted in increased levels of insulin-like growth factor 1 (IGF-1), an important mediator of GH’s anabolic actions.(7)(17)(18)(19)

GHRP-2 Peptide and Appetite Regulation

In a controlled study, two groups—one exposed to GHRP-2 and the other to saline—were given access to a buffet meal to assess food intake. The GHRP-2 group consumed 36% more food than the saline group, with increased energy intake per kilogram of body weight. GH levels were significantly higher in the GHRP-2 group, with researchers concluding that GHRP-2 stimulates appetite in a similar manner to ghrelin, suggesting its potential for investigating hunger regulation and eating behavior.(2)

GHRP-2 Peptide and Muscle Tissue Health

Studies on murine models of thermal injury showed that GHRP-2 reduced pro-inflammatory markers associated with muscle wasting, such as IL-6 and MuRF-1. These findings suggest that GHRP-2 may have a muscle-sparing effect, potentially reducing muscle protein breakdown and supporting muscle health in critical conditions. Additionally, case studies have indicated that GHRP-2 may promote muscle and weight gain, further emphasizing its potential for muscle recovery and growth.(20)(21)

GHRP-2 Peptide and Antioxidative Actions

GHRP-2 has shown potential antioxidative effects, with studies indicating its affinity for CD36, a receptor involved in the uptake of oxidized low-density lipoprotein (OxLDL). In experiments on ApoE(-/-) mouse models, GHRP-2 increased circulating IGF-1 levels and reduced superoxide production in the aorta, suggesting its potential to protect against atherosclerosis. GHRP-2 also lowered the expression of genes associated with oxidative stress and inflammation, making it a potential candidate for combating atherogenic processes and protecting vascular health.(15)

GHRP-2 Peptide and Inflammation

GHRP-2 has been shown to reduce inflammation in murine models of acute lung injury. The peptide decreased lung edema, neutrophil infiltration, and pro-inflammatory cytokine levels. It also suppressed nuclear factor-kappaB (NF-κB) activation, a key mediator of inflammation, offering potential benefits in inflammatory conditions.(16)

GHRP-2 Peptide and Growth Hormone Deficiency

GHRP-2 has been investigated as a diagnostic tool for growth hormone (GH) deficiency. In a study of research models, GHRP-2 was administered after overnight fasting, and GH levels peaked within one hour of exposure. This effect was consistent and reproducible, suggesting that GHRP-2 may serve as a reliable tool for diagnosing GH deficiency, offering an alternative to the insulin tolerance test (ITT). Additionally, combining GHRP-2 with GHRH further enhanced GH levels, showing promising results for GH deficiency diagnosis and treatment.(8)(9)

GHRP-2 Peptide in Combination with TRH and GnRH

In a study investigating the combined effects of GHRP-2 with Thyrotropin-Releasing Hormone (TRH) and Gonadotropin-Releasing Hormone (GnRH), the combination induced significant activation of GH secretion along with the stimulation of thyroid stimulating hormone (TSH) and luteinizing hormone (LH). This combination appeared to produce the most substantial metabolic effects, surpassing the actions of GHRP-2 alone or in combination with TRH, making it a potential candidate for addressing multiple hormonal axes.(10)

GHRP 2 peptide is available for research and laboratory purposes only. Please review and adhere to our Terms and Conditions before ordering.

References:

1. Garcia JM, Merriam GR, Kargi AY. Growth Hormone in Aging. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext. South Dartmouth (MA): MDText.com https://www.ncbi.nlm.nih.gov/books/NBK279163/
2. Laferrère, Blandine et al. “Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men.” The Journal of clinical endocrinology and metabolism vol. 90,2 (2005): 611-4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2824650/
3. Bowers CY. History to the discovery of ghrelin. Methods Enzymol. 2012;514:3-32. doi: 10.1016/B978-0-12-381272-8.00001-5. PMID: 22975043. https://pubmed.ncbi.nlm.nih.gov/22975043/
4. Roh SG, He ML, Matsunaga N, Hidaka S, Hidari H. Mechanisms of action of growth hormone-releasing peptide-2 in bovine pituitary cells. J Anim Sci. 1997 Oct;75(10):2744-8. doi: 10.2527/1997.75102744x. PMID: 9331879. https://pubmed.ncbi.nlm.nih.gov/9331879/
5. Asad Rahim, Stephen M. Shalet, in Growth Hormone Secretagogues, 1999. Does desensitization to growth hormone secretagogues occur? https://www.sciencedirect.com/topics/medicine-and-dentistry/pralmorelin
6. Furuta S, Shimada O, Doi N, Ukai K, Nakagawa T, Watanabe J, Imaizumi M. General pharmacology of KP-102 (GHRP-2), a potent growth hormone-releasing peptide. Arzneimittelforschung. 2004;54(12):868-80. doi: 10.1055/s-0031-1297042. PMID: 15646371. https://pubmed.ncbi.nlm.nih.gov/15646371/
7. Emanuela Arvat, Lidia Di Vito, Barbara Maccagno, Fabio Broglio, Muni F Boghen, Romano Deghenghi, Franco Camanni, Ezio Ghigo, 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, Volume 18, Issue 6, 1997, Pages 885-891, ISSN 0196-9781, https://doi.org/10.1016/S0196-9781(97)00016-8
8. Chihara K, Shimatsu A, Hizuka N, Tanaka T, Seino Y, Katofor Y; KP-102 Study Group. A simple diagnostic test using GH-releasing peptide-2 in adult GH deficiency. Eur J Endocrinol. 2007 Jul;157(1):19-27. doi: 10.1530/EJE-07-0066. https://pubmed.ncbi.nlm.nih.gov/17609397/
9. Pihoker C, Middleton R, Reynolds GA, Bowers CY, Badger TM. Diagnostic studies with intravenous and intranasal growth hormone-releasing peptide-2 in children of short stature. J Clin Endocrinol Metab. 1995 Oct;80(10):2987-92. https://pubmed.ncbi.nlm.nih.gov/7559885/
10. Van den Berghe G, Baxter RC, Weekers F, Wouters P, Bowers CY, Iranmanesh A, Veldhuis JD, Bouillon R. The combined administration of GH-releasing peptide-2 (GHRP-2), TRH and GnRH to men with prolonged critical illness evokes superior endocrine and metabolic effects compared to treatment with GHRP-2 alone. Clin Endocrinol (Oxf). 2002 May;56(5):655-69. https://pubmed.ncbi.nlm.nih.gov/12030918/
11. GHRP 2, GPA 748, Growth Hormone-Releasing Peptide 2, KP-102 D, KP-102 LN, KP-102D, KP-102 LN. https://link.springer.com/article/10.2165/00126839-200405040-00011#
12. Phung LT, Sasaki A, Lee HG, Vega RA, Matsunaga N, Hidaka S, Kuwayama H, Hidari H. Effects of the administration of growth hormone-releasing peptide-2 (GHRP-2) orally by gavage and in feed on growth hormone release in swine. Domest Anim Endocrinol. 2001 Jan;20(1):9-19. https://pubmed.ncbi.nlm.nih.gov/11164330/
13. Yin, Y., Li, Y., & Zhang, W. (2014). The growth hormone secretagogue receptor: its intracellular signaling and regulation. International journal of molecular sciences, 15(3), 4837–4855. https://doi.org/10.3390/ijms15034837
14. Sinha, D. K., Balasubramanian, A., Tatem, A. J., Rivera-Mirabal, J., Yu, J., Kovac, J., Pastuszak, A. W., & Lipshultz, L. I. (2020). Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal males. Translational andrology and urology, 9(Suppl 2), S149–S159. https://doi.org/10.21037/tau.2019.11.30
15. Titterington JS, Sukhanov S, Higashi Y, Vaughn C, Bowers C, Delafontaine P. Growth hormone-releasing peptide-2 suppresses vascular oxidative stress in ApoE-/- mice but does not reduce atherosclerosis. Endocrinology. 2009 Dec;150(12):5478-87. doi: 10.1210/en.2009-0283. Epub 2009 Oct 9. PMID: 19819949; PMCID: PMC2795722.
16. Li, G., Li, J., Zhou, Q., Song, X., Liang, H., & Huang, L. (2010). Growth hormone releasing peptide-2, a ghrelin agonist, attenuates lipopolysaccharide-induced acute lung injury in rats. The Tohoku journal of experimental medicine, 222(1), 7–13. https://doi.org/10.1620/tjem.222.7
17. Veldhuis, J. D., Keenan, D. M., Bailey, J. N., Adeniji, A. M., Miles, J. M., & Bowers, C. Y. (2009). Novel relationships of age, visceral adiposity, insulin-like growth factor (IGF)-I and IGF binding protein concentrations to growth hormone (GH) releasing-hormone and GH releasing-peptide efficacies in men during experimental hypogonadal clamp. The Journal of clinical endocrinology and metabolism, 94(6), 2137–2143. https://doi.org/10.1210/jc.2009-0136
18. Veldhuis, J. D., & Keenan, D. M. (2008). Secretagogues govern GH secretory-burst waveform and mass in healthy eugonadal and short-term hypogonadal men. European journal of endocrinology, 159(5), 547–554. https://doi.org/10.1530/EJE-08-0414
19. Bowers, C. Y., Granda, R., Mohan, S., Kuipers, J., Baylink, D., & Veldhuis, J. D. (2004). Sustained elevation of pulsatile growth hormone (GH) secretion and insulin-like growth factor I (IGF-I), IGF-binding protein-3 (IGFBP-3), and IGFBP-5 concentrations during 30-day continuous subcutaneous infusion of GH-releasing peptide-2 in older men and women. The Journal of clinical endocrinology and metabolism, 89(5), 2290–2300. https://doi.org/10.1210/jc.2003-031799
20. Sheriff, S., Joshi, R., Friend, L. A., James, J. H., & Balasubramaniam, A. (2009). Ghrelin receptor agonist, GHRP-2, attenuates burn injury-induced MuRF-1 and MAFbx expression and muscle proteolysis in rats. Peptides, 30(10), 1909–1913. https://doi.org/10.1016/j.peptides.2009.06.029
21. Sigalos, J. T., & Pastuszak, A. W. (2018). The Safety and Efficacy of Growth Hormone Secretagogues. Sexual medicine reviews, 6(1), 45–53. https://doi.org/10.1016/j.sxmr.2017.02.004