Anyone who has ever had a delicious piece of garlic bread knows that there is a price to pay for eating it: the dreaded garlic breath. What makes garlic so good at making your breath smell so bad? The main culprit is a compound called allyl methyl sulfide. As your body digests the garlic, the sulfide is released into your bloodstream. From there, it travels through your body until it is eliminated through your digestive system, your urine, or out of your pores. But some of the allyl methyl sulfide also crosses from the bloodstream into the air that fills your lungs. As you breathe this air out, the garlic smell goes with it. This is why no matter how many pieces of gum you chew, how often you brush your teeth, or how much mouthwash you swish, a garlicky meal can give you stinky breath for days.