Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue, or ghrelin-receptor agonist, peptide class. It is a five-amino-acid compound built as a selective ligand for the growth hormone secretagogue receptor.

In the published preclinical literature, ipamorelin has been characterised at the molecular level as a selective agonist at the growth hormone secretagogue receptor (GHSR-1a), the ghrelin receptor, studied in primary rat pituitary cell cultures and in animal models for receptor binding and pituitary signalling, with little reported cross-activity at other pituitary hormone pathways such as ACTH and cortisol across the ranges examined. It is supplied as a research compound and is not intended for human or veterinary use.