I have been purchasing Stronghold/Revolution for my dog from PetBucket for about 5 years. My dog has never had a flea on him. The medicine is supposed to prevent heartworms too, so to be sure it is working I had him tested for heartworms at his annual check-up and he is negative. So, this medicine is real/it works. I'm in the US and I receive it in about 14 days. I am so happy that PetBucket is in business because I save a lot of money and my dog gets good medicine. I also have recommended PetBucket to my friends.