There is a lot of counterfeit Frontline coming in from overseas. I buy only from USA sellers. Use the ask seller a question feature to find out: What is the country of manufacture?(It's on the back of the box) Real Frontline comes from USA, or France. Does it state: "MERIAL--EPA APPROVED"? ..Is the box sealed? The end of the box will have a seal with a "LOT #" This number must match the number on each tube inside the package
Thank You