Lufenuron details Product Name: Lufenuron CAS NO:  103055-07-8 Molecular Formula:C17H8Cl2F8N2O3 Formula Weight:  511.1502 Appearance: White crystalline power Assay: 98.0% min What is Lufenuron? Lufenuron is the active ingredient in the veterinary flea control medication Program, and one of the two active ingredients in the flea, heartworm, and anthelmintic medicine milbemycin oxime/lufenuron. Lufenuron is stored in the animal’s body fat and transferred to adult fleas through the host’s …