GHRP-2

GHRP-2 Overview

GHRP-2 Overview (Pralmorelin) is a synthetic, non-natural peptide that serves as a potent agonist of the growth hormone secretagogue receptor (GHS-R). It is classified as a second-generation growth hormone releasing peptide. Since its discovery, it has been primarily utilized in clinical research to investigate the mechanisms of the somatotropic axis. GHRP-2 is highly regarded for its ability to stimulate the pituitary gland to release endogenous growth hormone in a pulsatile manner, mimicking natural physiological rhythms more closely than exogenous hormone replacement.

In addition to its role as a diagnostic tool for growth hormone deficiency, researchers are exploring its systemic utility. Current clinical interest focuses on its potential to reverse muscle wasting (cachexia), improve recovery times in postoperative settings, and modulate the immune response through thymic rejuvenation. Its high degree of oral and sublingual activity distinguishes it from many other peptides, allowing for diverse experimental applications without the strict requirement of parenteral administration.

GHRP-2 Structure

The chemical composition of GHRP-2 is a hexapeptide sequence designed for metabolic stability and high receptor affinity.

Structure Solution Formula: D-Alanyl-3-(2-naphthyl)-D-alanyl-L-alanyl-L-tryptophyl-D-phenylalanyl-L-lysinamide

Sequence: D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2

This structure features specific D-isomer amino acids which protect the peptide from rapid enzymatic degradation by dipeptidyl peptidase-4 and other common proteases, extending its half-life in research environments.

GHRP-2 Effects

1. Muscle Protein Kinematics

GHRP-2 research in bovine and porcine models demonstrates a significant shift in nitrogen balance. The peptide promotes muscle preservation by suppressing the expression of Atrogin-1 and MuRF1, which are the primary ligases responsible for cellular protein breakdown. By inhibiting these catabolic signals, GHRP-2 maintains muscle fiber integrity during periods of starvation or chronic illness.

2. Orexigenic Modulation

GHRP-2 acts on the hypothalamus to stimulate appetite through the ghrelin pathway. In subjects with chronic wasting diseases, this orexigenic effect is vital for maintaining nutritional status. Research indicates that even in cases of obesity, the body remains responsive to the hunger-inducing signals of GHRP-2, suggesting its role in complex metabolic signaling.

3. Cardioprotective Mechanisms

Experimental data suggests that GHRP-2 prevents cardiomyocyte apoptosis. This is achieved by stabilizing mitochondrial membranes and reducing oxidative stress within heart tissue. By identifying a specific GHS receptor in the heart, scientists have opened new avenues for investigating how peptides can protect the cardiovascular system from ischemic damage.

4. Immunosenescence Reversal

The decline of the thymus gland is a hallmark of aging. GHRP-2 has been shown to rejuvenate this organ, increasing the output of naive T-cells. This suggests a potential role in enhancing vaccine responsiveness and general pathogen resistance in elderly research subjects.

5. Sleep Architecture and Recovery

GHRP-2 administration has been linked to a profound increase in slow-wave sleep. This stage of sleep is critical for physical repair and cognitive health. Research shows a significant increase in the duration of stages 3 and 4 sleep, alongside a moderate increase in REM sleep, leading to improved daytime energy and healing markers.

6. Antinociceptive Properties

GHRP-2 demonstrates a direct effect on pain perception by acting on the opioid system. It shows selectivity for receptors that manage pain relief without the high risk of respiratory depression typically associated with traditional analgesics. This makes it a primary candidate for studying alternative pain management strategies.

Research Comparison Table

Property

Clinical Observation

Target System

Growth Hormone Release

Pulsatile Secretion

Pituitary Gland

Muscle Impact

Inhibition of Atrogin-1

Skeletal Muscle

Metabolic Impact

Ghrelin Agonism

Hypothalamus

Cardiac Impact

Reduced Apoptosis

Heart Myocytes

Immune Impact

T-cell Proliferation

Thymus Gland

Neurological Impact

Increased Deep Sleep

CNS

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 is a leading expert in peptide chemistry and pharmacologie endocrinologie. With a career spanning over three decades at CNRS and Sanofi, he has contributed to over 100 scientific publications. His research is foundational to our understanding of ghrelin receptor ligands and the development of GHRP-2.

Dr. Fehrentz is cited here for his academic contributions. He is not affiliated with Peptide Sciences, nor does he endorse or advocate for the use or sale of this product.

Storage

For maximum stability, GHRP-2 should be stored as a lyophilized powder at -20 degrees Celsius. Once reconstituted, the solution must be kept in a sterile environment at 2 to 8 degrees Celsius. Avoid exposure to UV light and fluctuating temperatures to prevent peptide denaturation.

Referenced Citations

[1] R. Hu et al., PloS One, vol. 11, no. 2, 2016.

[2] D. Yamamoto et al., Life Sci., vol. 82, no. 9–10, 2008.

[3] L. T. Phung et al., Domest. Anim. Endocrinol., vol. 18, no. 3, 2000.

[4] B. Laferrere et al., J. Clin. Endocrinol. Metab., vol. 90, no. 2, 2005.

[5] B. Laferrere et al., Obes. Silver Spring Md, vol. 14, no. 6, 2006.

[6] G. Muccioli et al., Ann. Endocrinol., vol. 61, no. 1, 2000.

[7] V. Bodart et al., Circ. Res., vol. 85, no. 9, 1999.

[8] D. D. Taub et al., Curr. Opin. Pharmacol., vol. 10, no. 4, 2010.

[9] G. Gopinadh et al., Neuroendocrinology, vol. 66, no. 4, 1997.

[10] P. Zeng et al., Peptides, vol. 55, 2014.

[11] Moulin, A. et al., ChemMedChem, 2: 1242-1259, 2007.