Cetrorelix acetate is a synthetic decapeptide with gonadotropin-releasing hormone (GnRH) antagonistic activity. Cetrorelix acetate is an analog of native GnRH with substitutions of amino acids at positions 1, 2, 3, 6, and 10. The molecular formula is C70H92CIN17O14 (Ac-D-Nal1-D-Cpa2-D-Pal3-Ser4-Tyr5- D-Cit6-Leu7-Arg8-Pro9-D -Ala10-NH2), and the molecular weight is 1431 Dalton, calculated as the anhydrous free base.