Ipamorelin, also known as NNC 26-0161, is a synthetic peptide that functions as a growth hormone secretagogue. It is a pentapeptide with the sequence Aib-His-D-2-Nal-D-Phe-Lys-NH2, which was developed to mimic the effects of ghrelin, a natural hormone that stimulates growth hormone release. Researchers have synthesized Ipamorelin to explore its potential in various therapeutic applications, particularly those related to growth hormone deficiencies. The compound is typically synthesized using solid-phase peptide synthesis techniques. Researchers have primarily investigated Ipamorelin for its ability to stimulate the release of growth hormone from the pituitary gland. Studies have shown that it can increase growth hormone levels without significantly affecting cortisol or prolactin levels, which are often influenced by other secretagogues. This selective action makes Ipamorelin a subject of interest in the treatment of growth hormone deficiencies and related conditions. Additionally, its potential benefits in muscle growth and repair have been explored in preclinical studies. Ipamorelin acts by binding to the growth hormone secretagogue receptor (GHSR), which is a G-protein-coupled receptor. This interaction stimulates the release of growth hormone from the anterior pituitary gland. Unlike some other secretagogues, Ipamorelin does not significantly affect the release of other hormones such as cortisol, making it a more selective option for growth hormone stimulation. The pharmacokinetic properties of Ipamorelin include a relatively short half-life, with subcutaneous administration resulting in a half-life of approximately 2 hours. It is considered stable when stored appropriately, but its bioavailability can vary depending on the route of administration. Researchers have noted that oral bioavailability is poor, limiting its use to injectable forms. Current research on Ipamorelin is focused on its potential therapeutic applications, particularly in conditions involving growth hormone deficiencies. As of now, Ipamorelin is not approved for clinical use by major regulatory agencies, and its use is primarily restricted to research settings. It remains a compound of interest due to its selective action and potential benefits in muscle growth and repair.