Caerulein, desulfated is the desulfurated form of Caerulein which is a decapeptide and a potent cholecystokinin receptor agonist. Ceruletide is a safe and effective cholecystokinetic agent with a direct spasmogenic effect on the gallbladder muscle and bile ducts.
Johnson LR, Stening GF, Grossman MI. Effect of sulfation on the gastrointestinal actions of caerulein. Gastroenterology. 1970 Feb;58(2):208-16. PMID: 4904949.