Once taken daily for 30 days, helps stop misquito bites, ticks and more. You need to take it every day for humans and pets for at least 30 days then you will begin to see the results and you won’t need any heartworm preventative cause if you prevent misquito bites, you stop heartworm. Great stuff, worked on both dogs and both of us as well. They hate the smell and taste of garlic.