Cholecystokinin (CCK) wani sinadari ne wanda sel masu rufin hanji ke samar da su a cikin jini. Babban aikinsa shi ne tada ƙwanƙwasa gallbladder, yana haifar da sakin bile a cikin ƙananan hanji don taimakawa wajen narkewar mai. Hakanan CCK yana aiki azaman mai hana yunwa, yana rage sha'awar abinci da rage zubar da abinci daga ciki zuwa cikin ƙananan hanji.
