Ipamorelin, a synthetic peptide derived from GHRP-1, is made up of five amino acids . Ipamorelin is a powerful growth hormone releasing peptide and is capable of causing potent growth hormone release . Ipamorelin stimulates the release of growth hormone by activating the ghrelin receptor found in the brain. Activating this receptor and increasing the levels of growth hormone within the body can modulate food intake and energy metabolism and also influences glucose and fat metabolism [2, 3]. Growth hormone secretion also increases appetite and causes increased lean muscle growth . Ipamorelin has been demonstrated to be a highly specific growth hormone stimulator since it does not lead to increases in prolactin, follicle-stimulating hormone, luteinizing hormone, or thyroid-stimulating hormone . Furthermore, the peptide does not cause adrenocorticotropic hormone or cortisol stimulation. Therefore, compared to other growth hormone stimulators, such as GHRP-2 and GHRP-6, ipamorelin is a more specific growth hormone stimulator. This means that ipamorelin does not possess lipogenic properties and it does not promote hunger. Furthermore, it is at least as potent as GHRP-6 and almost as potent as GHRP-2. Animal studies have shown that ipamorelin can counteract a reduction in bone and muscle strength . In human trials, ipamorelin was shown to induce substantial and dose dependent growth hormone release in healthy males . Another human study also determined that ipamorelin strongly induces growth hormone release over a range of doses and that the half-life of the peptide is two hours . In summary, ipamorelin is a potent growth hormone stimulator that does not broadly affect additional biochemical pathways like some other GHRPs. The optimal way to use ipamorelin is to stack it with low doses of other growth hormone releasing peptides, such as GHRP-2, GHRP-6 or hexarelin. Combining a low dose of ipamorelin with an additional GHRP will increase the pulse of human growth hormone. Ipamorelin should be reconstituted in BAC water and injected subcutaneously or intramuscularly at a dosage of 200 mcg. Ipamorelin can be dosed once or twice daily and dosages should be spread out over the course of 24 hours. Ipamorelin has been acutely administered to humans at 100 mcg/kg with no adverse effects reported. The peptide has also been administered at 30 mcg/kg twice daily for up to 7 days and was well tolerated . The highly specific actions of ipamorelin give it a positive safety profile and side effects when using ipamorelin at the recommended dose are generally minimal, although headaches have been reported. References 1. Raun, K., et al., Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol, 1998. 139(5): p. 552-61. 2. Hosoda, H., M. Kojima, and K. Kangawa, Biological, physiological, and pharmacological aspects of ghrelin. J Pharmacol Sci, 2006. 100(5): p. 398-410. 3. Sun, Y., et al., Ghrelin stimulation of growth hormone release and appetite is mediated through the growth hormone secretagogue receptor. Proc Natl Acad Sci U S A, 2004. 101(13): p. 4679-84. 4. Laferr�re, B., et al., Growth Hormone Releasing Peptide -2 (GHRP-2), like ghrelin, increases food intake in healthy men. The Journal of clinical endocrinology and metabolism, 2005. 90(2): p. 611-614. 5. Andersen, N.B., et al., The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult rats. Growth Horm IGF Res, 2001. 11(5): p. 266-72. 6. Rasmussen, M.H., et al., Ipamorelin � A novel very potent growth hormone secretagogue. Growth Hormone & IGF Research, 1998. 8(4): p. 332. 7. Gobburu, J.V., et al., Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers. Pharm Res, 1999. 16(9): p. 1412-6. 8. Beck, D.E., 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. 29(12): p. 1527-1534.