Note: Once foil is opened test needs to be used within 1 hour. The presence of Ketones is the body's signal that there is a problem with you diabetes control High levels of Ketones can form when you burn too much fat for energy and if untreated, can lead to serious complications. This is a convenient and easy way to test for the presence and concentration of urinary ketones : What Is Ketosis? On a low-carb diet such as the Atkins Diet, you must aim for a state of ketosis. Ketosis occurs when your body stops burning carbohydrates for energy and switches to burning fat. You should go into this state during the first few days of the plan, as soon as you begin depriving your body of carbohydrates and supplying it with mainly fat and protein. During ketosis, your body produces ketones. Why do I need these tests? These tests detect ketones in the urine and so will give an indication on whether you are in a state of ketosis or not. There is 1 Test strip in each sealed foil. The product must be kept out of sunlight with the lid on when not being used to ensure the quality of the strip.