Ipamorelin peptide is comprised of five amino acids (pentapeptide) and is formally known as a ‘growth hormone secretagogue’. Ipamorelin peptide appears to act via ghrelin receptor binding, though its mechanism of action is still under investigation by researchers. It is considered a growth hormone secretagogue (GHS-R) with potential in regulating energy and weight. Ipamorelin peptide is a synthetic peptide, with specific potential similar to growth hormones (HGH). After conducting several research studies and laboratory reviews, Ipamorelin was identified as a pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) with the potential to trigger the pituitary gland and stimulate the release of growth hormones.(3)
Ipamorelin is the first synthetic growth hormone secretagogue which has the potential to augment production of natural growth hormone.(3) This peptide has a high potential selectivity for the growth receptors in the gland, similar to the growth hormone receptor peptide (GHRP) receptor agonists, with possible binding activity on GHRP receptors to secrete possible increase in growth hormone production.(3)
Based on multiple research studies, it was suggested that unlike other HGH stimulating hormones, Ipamorelin may not increase the cortisol and Adrenocorticotropic (ACH) hormone levels significantly in blood plasma. As a result, Ipamorelin may be a GHRP-receptor agonist with a high selectivity for growth hormone release, possibly without affecting the ACH and cortisol levels.
Research and Clinical Studies
Ipamorelin Peptide and Initial Research
Based on one 1998 research study, Ipamorelin, when presented to rats, may release growth hormones from the pituitary cells. When Ipamorelin was presented to swine and pentobarbitone anaesthetized rats, it reportedly exibited release in growth hormones. Upon further observation, the researchers hypothesized that similar to other growth hormone (GH) stimulating peptides, Ipamorelin may be a growth receptor agonist stimulating GH release through potential affinity in growth hormone receptors.(3)
In 1999, additional research was carried out in adult female rats where Ipamorelin was presented three times daily. Post delivery for 15 days, it was suggested by the scientists that not only were growth hormone levels apparently elevated, but the longitudinal bone growth rate (LGR) was also appeared to be increased from 42 micro meter per day to up to 52 micrometer per day.(4)
In late 1999, a clinical trial was carried out on 8 male subjects where Ipamorelin was presented every 15 minutes for a set period. After 2 hours post study, it was reported by the researchers that the levels of growth hormones had apparently exponentially increased with the highest peak recorded within a single episode of the peptide.(5)
Ipamorelin Peptide and Growth Deficiencies
Since 2001, there have been multiple clinical studies on subjects with growth hormone deficiency. Growth hormone releasing peptides had exhibited some potential through two possible actions – (i) via potential stimulation of the pituitary gland to release growth hormones and (ii) via potential action on the arcuate nucleus of the hypothalamus. While these peptides, including Ipamorelin, were reported to induce high releases of growth hormones, it remains unclear which of the two mechanisms was utilized.(6)
Six subjects with growth hormone deficiency and growth failure were presented with graded concentrations of the peptide over eight months. Throughout this study, the subjects were monitored every 12 hours for episodic growth hormone secretion and toxicity levels. After two months, researchers reported that subjects exhibited an apparent spike in growth hormone levels during the trial, with little effect on the GH levels reported at the later stages.(7)
Ipamorelin peptide is available for research and laboratory purposes only. Please review and adhere to our Terms and Conditions before ordering.
- A Giustina, JD Veldhius, Pathophysiology of the neuro regulation of growth hormone secretion in experimental animals and the human, Endocrinology, 1 December 1998.
- David E. Beck et al., Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients, International Journal of Colorectal Disease, 2014.
- K. Raun et al., Ipamorelin, the first selective growth hormone secretagogue, Endocrinology, November 1998.
- P.B Johansen et al, Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats, Growth Hormone IGF Research, April 1999.
- Gobburu, J.V.S., Agersø, H., Jusko, W.J. et al. Pharmacokinetic-Pharmacodynamic Modeling of Ipamorelin, a Growth Hormone Releasing Peptide, in Human Volunteers. Pharm Res 16, 1412–1416 (1999).
- Rogério G. Gondo et al, Growth Hormone-Releasing Peptide-2 Stimulates GH Secretion in GH-Deficient Patients with Mutated GH-Releasing Hormone Receptor, The Journal of Clinical Endocrinology & Metabolism, Volume 86, Issue 7, 1 July 2001, Pages 3279–3283.
- Mericq V, Cassorla F, Salazar T, Avila A, Iñiguez G, Bowers CY, Merriam GR. Effects of eight months treatment with graded doses of a growth hormone (GH)-releasing peptide in GH-deficient children. J Clin Endocrinol Metabolism, Jul 1998; 83(7):2355-60.
- 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–S15.
Dr. Marinov (MD, Ph.D.) is a researcher and chief assistant professor in Preventative Medicine & Public Health. Prior to his professorship, Dr. Marinov practiced preventative, evidence-based medicine with an emphasis on Nutrition and Dietetics. He is widely published in international peer-reviewed scientific journals and specializes in peptide therapy research.