GHRP-2 Yields Physiologic Growth Hormone Release

GHRP-2 (growth hormone releasing peptide-2) is a synthetic version of ghrelin resembling Sermorelin,  that has been found to cause GH release. GHRP-2 is sometimes referred to as a second-generation GHRP as it was produced after initial research into molecules like GHRP-6. GHRP-2 is under investigation for use in growth hormone (GH) deficiency because it may produce a more physiologic effect than exogenous administration of recombinant growth hormone (rGH).

Drawbacks to Synthetic Growth Hormone

There are several problems with rGH. The first problem is due to the fact that GH can only be administered as boluses and often not in response to any particular physiologic state (i.e. eating, sleeping, etc.). GH release, under normal conditions, occurs in a pulsatile manner and never as a once-per-day bolus. It also fluctuates in response to sleep, exercise, food consumption, and several other factors.

The second problem with rGH is that it produces “square-wave” effects where levels rise and fall rapidly. Under normal circumstances, GH levels rise slowly to a peak and then fall again over time. The pattern looks more like a gentle wave, with peaks and valleys, rather than a box-like shape with steep on and off slopes.

The final problem with rGH injections is that they contain just one of the known variants of GH. Though the variants are similar in many ways, their subtle differences result in different activity levels in different tissues. The body produces these variants in different proportions in response to specific signals. With rGH injections, there is no way to control which GH variants are being injected and no way to alter those variants in response to physiologic signals.

Benefits of GHRP-2

GHRP-2 is a peptide, but it the peptide itself affects GH at an early stage in its production. This allows many normal physiologic controls to remain intact. In animal studies, GHRP-2 produced more normal pulsatile secretion of GH, more normal wave patterns, and almost no change in GH variant concentrations[1], [2]. Additionally, GHRP-2 has less impact on appetite than other GHRPs and so does not interfere with normal ghrelin signaling as much[3]. The result is that GHRP-2 more closely mimics normal mammalian physiology than recombinant GH or other GHRPs.



[1] L. T. Phung, H. Inoue, V. Nou, H. G. Lee, R. A. Vega, N. Matsunaga, S. Hidaka, H. Kuwayama, and H. Hidari, “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.

[2] G. Baumann, “Growth hormone heterogeneity: genes, isohormones, variants, and binding proteins,” Endocr. Rev., vol. 12, no. 4, pp. 424-449, Nov. 1991. Get full information at

[3] 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.