Tesamorelin is a synthetic 44-amino acid peptide analogue of endogenous growth hormone-releasing hormone (GHRH), modified with a trans-3-hexenoic acid group at the N-terminus to increase stability. It is the only GHRH analogue to have received FDA approval for a specific indication, making it a well-characterized research tool for studying the GH/IGF-1 axis.

AOD-9604 (Anti-Obesity Drug 9604) is a synthetic peptide corresponding to amino acids 176-191 of human growth hormone (hGH), with an additional tyrosine residue at the N-terminus. It was developed as a research tool to study the lipolytic activity of hGH independently of its growth-promoting and insulin-sensitizing effects.