When you first enter ketosis, you will be able to smell ketones on your breath and even in your urine . Some describe this smell as sweet and fruity (or smelling of overripe fruit) and others say it's akin to nail-polish remover. Whatever the case may be, know that this smell is strong and noticeable. It's the result of either acetone or acetoacetate. Some ketoers also experience a metallic taste in mouth in addition to having ketosis (keto) breath.