Be wary when buying flea & tick medications on ebay. I recently tried this for the first time to save money, I purchases a 3 pack of frontline from a American seller, but it was a overseas marked box. It looked exactly the same as every frontline box I've ever used with the exception of some foreign language on the box, even the vials of medication where the same. The problem with the product is it did not work at all! I ended up dosing my dog twice during the first week and then again two weeks after that. It seemed the medication did nothing. I went to my local vet and bought another box of Frontline and it worked just fine, no fleas.