Pharmacological characteristics of KP-102 (GHRP-2), a potent growth hormone-releasing peptide.
Doi. Naomi N; Hirotani. Chiharu C; Ukai. Kiyoharu K; Shimada. Osafumi O; Okuno. Tadashi T; Kurasaki. Shigeru S; Kiyofuji. Takeshi T; Ikegami. Reiko R; Futamata. Machiko M; Nakagawa. Terutake T; Ase. Katsuhiko K; Chihara. Kazuo K
Key Findings
- GHRP‑2 triggers a stronger GH release than injected GHRH in conscious rats and works in conscious dogs where GHRH fails.
- Its GH‑releasing action is less inhibited by somatostatin and requires the median eminence (endogenous GHRH) for full potency.
- Three weeks of daily GHRP‑2 leads to modest growth acceleration, slight weight gain, and increased wet weight of some organs, with mild ACTH/corticosterone rise.
Practical Outcomes
- For biohackers, GHRP‑2 appears to be a reliable GH‑boosting peptide that works even when somatostatin is high, making it potentially more effective than GHRH analogs. A typical protocol might involve daily sub‑cutaneous dosing for several weeks to see modest growth and weight effects, while monitoring ACTH‑related stress responses. No major safety concerns are highlighted, but users should be aware of the slight increase in stress hormones.
Summary
GHRP‑2 (KP‑102) is a strong synthetic peptide that makes the body release growth hormone (GH) more effectively than the natural hormone GHRH, especially when you’re awake. It works in rats and dogs, isn’t blocked much by the body’s own GH‑suppressing hormone somatostatin, and needs the brain’s median eminence (where GHRH lives) to reach its full effect. Short‑term use (3 weeks) can boost growth and slightly increase body and organ weight, while also nudging up stress hormones (ACTH and corticosterone) but not prolactin.
Abstract
KP-102 (D-alanyl-3-(2-naphthyl)-D-alanyl-L-alanyl-L-tryptophyl-D-phenylalanyl-L-lysinamide dihydrochloride, growth hormone-releasing peptide-2, GHRP-2, pralmorelin, CAS 158861-67-7), is a potent synthetic growth hormone (GH) secretagogue. In the present study, the pharmacological characteristics of the GH-releasing property of KP-102 were investigated by means of in vivo and in vitro experiments. In conscious rats, the GH-releasing activity of KP-102 was more potent than that of exogenously injected GH-releasing hormone (GHRH). Under pentobarbital anesthesia in which endogenous somatostatin secretion is known to be decreased, KP-102 and GHRH, both showed an almost equivalent GH-releasing potency, which was also similar to that of KP-102 in conscious rats. Besides, KP-102 showed GH-releasing activity in conscious dogs as well, while GHRH failed to increase serum GH levels in conscious dogs. These findings suggest that the GH-releasing activity of KP-102 was less sensitive to GH suppression by endogenous somatostatin as compared with that of GHRH. The GH-releasing activity of KP-102 was completely absent in hypophysectomized rats, but present in median eminence-lesioned rats in which secreted GH amounts were significantly less than those normal rats, indicating necessity of the median eminence (endogenous GHRH) to exert the full activity of KP-102 in GH stimulation. KP-102 directly stimulated GH secretion from cultured rat anterior pituitary cells, although the GH-releasing potency of KP-102 was significantly weaker than that of GHRH in vitro. In conscious rats, KP-102 stimulated the secretion of both adrenocorticotrophic hormone (ACTH) and corticosterone, but not of prolactin. Three weeks administration of KP-102 showed growth-accelerating effect, a slight increase of body weight and wet weight of some organs in both normal and monosodium glutamate (MSG)-treated rats. These results suggest that KP-102 showed specific GH-releasing activity apart from slight ACTH secretion, and that the GH-releasing activity was stable in comparison with that of exogenously injected GHRH.
Study Information
pubmed
2004
2004-12-01T00:00:00.000Z
10.1055/s-0031-1297041
14
43