Aspartame is commonly used as a tabletop sweetener, as a sweetener in prepared foods and beverages, and in recipes that do not require too much heating (since heat breaks down aspartame). It can also be found as a flavoring in some medicines.
In the body, aspartame is broken down into phenylalanine, aspartic acid, and methanol. Methanol can be toxic in high amounts, but the amounts that result from the breakdown of aspartame is lower than with many “natural” foods. For example, drinking a liter of diet soda would lead to consumption of 55 milligrams (mg) of methanol, as compared to as much as 680 mg of methanol from a liter of fruit juice