The introduction of Ipamorelin

Description

Ipamorelin is a new and potent synthetic pentapeptide with distinct and specific growth hormone (GH)--releasing properties.

Mechanism of action

It works by binding to IGF-1 receptors in the body and mimicking its effects on those receptors. This causes an increase in muscle mass and strength and fat loss due to increased metabolism and lipolysis (the breakdown of fat).

Biological activity

Ipamorelin is a pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2), which displays high GH-releasing potency and efficacy in vitro and in vivo. As an outcome of a major chemistry programme, ipamorelin was identified within a series of compounds lacking the central dipeptide Ala-Trp of growth hormone-releasing peptide (GHRP)-1. In vitro, ipamorelin released GH from primary rat pituitary cells with a potency and efficacy similar to GHRP-6 (ECs) = 1.3+/-0.4nmol/l and Emax = 85+/-5% vs 2.2+/-0.3nmol/l and 100%). A pharmacological profiling using GHRP and growth hormone-releasing hormone (GHRH) antagonists demonstrated that ipamorelin, like GHRP-6, stimulates GH release via a GHRP-like receptor. In pentobarbital anaesthetised rats, ipamorelin released GH with a potency and efficacy comparable to GHRP-6 (ED50 = 80+/-42nmol/kg and Emax = 1545+/-250ng GH/ml vs 115+/-36nmol/kg and 1167+/-120ng GH/ml). In conscious swine, ipamorelin released GH with an ED50 = 2.3+/-0.03 nmol/kg and an Emax = 65+/-0.2 ng GH/ml plasma. Again, this was very similar to GHRP-6 (ED50 = 3.9+/-1.4 nmol/kg and Emax = 74+/-7ng GH/ml plasma). GHRP-2 displayed higher potency but lower efficacy (ED50 = 0.6 nmol/kg and Emax = 56+/-6 ng GH/ml plasma). The specificity for GH release was studied in swine. None of the GH secretagogues tested affected FSH, LH, PRL or TSH plasma levels. Administration of both GHRP-6 and GHRP-2 resulted in increased plasma levels of ACTH and cortisol. Very surprisingly, ipamorelin did not release ACTH or cortisol in levels significantly different from those observed following GHRH stimulation. This lack of effect on ACTH and cortisol plasma levels was evident even at doses more than 200-fold higher than the ED50 for GH release. In conclusion, ipamorelin is the first GHRP-receptor agonist with a selectivity for GH release similar to that displayed by GHRH.

Side effects

Although Ipamorelin is relatively safe to administer, like all medications, it can cause specific side effects when introduced to the human body. Men using ipamorelin therapy have reported experiencing several common side effects, which include:

Dry mouth

Lightheadedness

Fever

Itching or pain at the injection site

Nausea

Headaches

Since Ipamorelin's primary function is to boost growth hormone production, it can also cause other serious side effects due to the elevating GH levels, including an increased risk of severe diseases.