GHRP-2

What is GHRP-2?

GHRP-2 (also called pralmorelin) is a synthetic growth hormone secretagogue recognized for its binding to the ghrelin/growth hormone secretagogue receptor. It was the first in its class of hormone secretagogues to be introduced and is currently marketed as a test peptide for hormone deficiency. Due to its efficacy in reducing ghrelin signaling and maintaining muscle fibers, it has been investigated in stage II clinical trials for the assessment of short stature and is under active research for its effects on appetite, muscle growth, the immune system, and sleep cycles. GHRP-2 is orally and sublingually active, so it does not need injection to deliver its effects.

GHRP-2 Effects

1. Protects and Enhances Muscle Structure

Research in Yaks indicates that GHRP-2 can amplify muscle growth in two ways: increased protein deposition and decreased protein degradation. The research showed that GHRP-2 can overcome natural growth plateaus that occur in yaks due to food deprivation, disease, and adverse environmental conditions on a cold, dry Tibetan plateau. Findings from this study reveal that GHRP-2 reduces muscle atrophy by inactivating atrogin-1 and MuRF1, proteins that control the muscle degradation pathways. There is hope that these findings could be used to reduce the catabolism common in chronic illnesses like autoimmune disease, cancer, and more.

By activating growth hormone and insulin-like growth factor-1, GHRP-2 helps to amplify muscle protein deposition. The combined effect of reducing degradation and amplifying deposition is that GHRP-2 encourages the development of lean body mass even in adverse conditions.

2. Stimulates Appetite

GHRP-2 has been shown to amplify food intake. Though this may not seem immediately important, appetite stimulation in the setting of chronic disease is an important part of overall health care. The ability to safely and reliably supplement food intake can treat chronically ill patients and improve long-term outcomes.

3. May Protect the Heart

Research in fetal heart cell culture lines shows that GHRP-2 and its analogues (GHRP-1 and GHRP-6) can shield heart cells by reducing apoptosis or programmed cell death. This is likely the result of direct protective effects on mitochondria, which may be particularly prone to apoptosis due to decreased blood and nutrient supply. Research in dogs has shown that GHRP-2 administration has beneficial effects on the heart through a specific receptor for these peptides. Identifying new receptors in any tissue opens pathways for new drug development that allows scientists to understand more of human physiology and how to prevent dysfunction in the first place.

4. Improves the Immune System

GHRP-2 has been shown to stimulate the thymus, an organ responsible for producing mature cells of the immune system. In doing so, GHRP-2 helps to ensure that necessary T-cells crucial for adaptive immunity and our ability to fight off complex infections are produced. Function of the thymus is known to decline with age. GHRP-2 can help to fight off infections, guard against cancer, and maintain normal tissue function. GHRP-2 has been shown to rejuvenate the thymus and increase the number and diversity of T-cells produced. This leads to amplified immunity.

5. Improves Sleep Quality

GHRP-2 has been shown to amplify the duration of stages 3 and 4 of the sleep cycles by about 50% each while increasing REM sleep by approximately 20%. Overall, these effects translate to significant improvement in sleep that leads to improvement in cognitive function, blood pressure, healing, and energy levels. These findings, while useful in all ages, are particularly important to the elderly, where the effects of aging take a toll on sleep quality. GHRP-2 may be useful in understanding how to fine-tune sleep patterns and helps people achieve benefits of quality sleep.

6. May Affect Pain Perception

It was originally thought that observations of decreased pain in animal models of osteoarthritis were the result of GHRP-2 inducing growth hormone secretion and accelerating healing in damaged tissues. Scientists observed, however, that pain was reduced before GHRP-2 could stimulate growth hormone levels and therefore had direct effects on pain perception. As it turns out, GHRP-2 has action on opioid receptors.

There are five known opioid receptors. Most opioid pain medications do not discriminate between them. The analgesic properties of medications like morphine affect things like wakefulness and breathing while others impact addiction. GHRP-2 is a selective opioid receptor agonist binding primarily to the receptor responsible for pain relief. This finding indicates that it may be possible to produce opioid medications that provide pain relief without undesirable effects like respiratory depression and addiction.

GHRP-2 exhibits minimal to moderate side effects, low oral and excellent subcutaneous bioavailability in mice. Per-kg dosage in mice does not directly translate to humans. GHRP-2 at Peptide Sciences is limited to educational and scientific research only, not for human consumption. Only buy GHRP-2 if you are a licensed research professional.

Article Author

The above literature was researched, edited and organized by Dr. Logan, M.D. Dr. Logan holds a doctorate degree from Case Western Reserve University School of Medicine and a B.S. in molecular biology.

Scientific Journal Author

Jean-Alain Fehrentz was born in Nancy, France, in 1955. He received his Ph.D. degree in Chemistry from the University of Nancy in 1983 and joined the Centre CNRS (INSERM in Pharmacologie Endocrinologie) of Montpellier in the research group of Professor B. Castro. From 1988 to 1992 he was appointed as researcher at Sanofi Research in Montpellier. Then he moved to the Faculty of Pharmacy of Montpellier, working under the direction of Professor J. Martinez. His research focus encompasses peptide synthesis, enzyme inhibitors, peptidomimetics, growth hormone interactions, and heterocyclic based receptor ligands. He has published more than 100 scientific publications.

Jean-Alain Fehrentz is being referenced as one of the leading scientists involved in the research and development of GHRP-2. In no way is this doctor/scientist endorsing or advocating the purchase, sale, or use of this product for any reason. There is no affiliation or relationship, implied or otherwise, between Peptide Sciences and this doctor. The purpose of citing the doctor is to acknowledge, recognize, and credit the exhaustive research and development efforts conducted by the scientists studying this peptide.

Referenced Citations

1. R. Hu et al., "Effects of GHRP-2 and Cysteamine Administration on Growth Performance, Somatotropic Axis Hormone and Muscle Protein Deposition in Yaks (Bos grunniens) with Growth Retardation," PloS One, vol. 11, no. 2, p. e0149461, 2016.
2. D. Yamamoto et al., "GHRP-2, a GHS-R agonist, directly acts on myocytes to attenuate the dexamethasone-induced expressions of muscle-specific ubiquitin ligases, Atrogin-1 and MuRF1," Life Sci., vol. 82, no. 9–10, pp. 460–466, Feb. 2008.
3. L. T. Phung et al., "The effects of growth hormone-releasing peptide-2 (GHRP-2) on the release of growth hormone and growth performance in swine," Domest. Anim. Endocrinol., vol. 18, no. 3, pp. 279–291, Apr. 2000.
4. B. Laferrère, C. Abraham, C. D. Russell, and C. Y. Bowers, "Growth hormone releasing peptide-2 (GHRP-2), like ghrelin, increases food intake in healthy men," J. Clin. Endocrinol. Metab., vol. 90, no. 2, pp. 611–614, Feb. 2005.
5. B. Laferrère, A. B. Hart, and C. Y. Bowers, "Obese subjects respond to the stimulatory effect of the ghrelin agonist growth hormone-releasing peptide-2 on food intake," Obes. Silver Spring Md, vol. 14, no. 6, pp. 1056–1063, Jun. 2006.
6. G. Muccioli et al., "Growth hormone-releasing peptides and the cardiovascular system," Ann. Endocrinol., vol. 61, no. 1, pp. 27–31, Feb. 2000.
7. V. Bodart et al., "Identification and characterization of a new growth hormone-releasing peptide receptor in the heart," Circ. Res., vol. 85, no. 9, pp. 796–802, Oct. 1999.
8. D. D. Taub, W. J. Murphy, and D. L. Longo, "Rejuvenation of the aging thymus: growth hormone-mediated and ghrelin-mediated signaling pathways," Curr. Opin. Pharmacol., vol. 10, no. 4, pp. 408–424, Aug. 2010.
9. G. Gopinadh et al., "Prolonged oral treatment with MK-677, a novel growth hormone secretagogue, improves sleep quality in man," Neuroendocrinology, vol. 66, no. 4, pp. 278–286, Oct. 1997.
10. P. Zeng et al., "Ghrelin receptor agonist, GHRP-2, produces antinociceptive effects at the supraspinal level via the opioid receptor in mice," Peptides, vol. 55, pp. 103–109, May 2014.
11. Moulin, A., Ryan, J., Martinez, J. and Fehrentz, J. (2007), Recent Developments in Ghrelin Receptor Ligands. ChemMedChem, 2: 1242-1259.