Malic Acid can be used to boost performance in physical activities as it is used in many supplements. Malic Acid can promote energy production and increase exercise endurance and can be used to fight off muscle fatigue. Malic acid can increase urine pH and citrate levels which could, in turn, make the formation of something like kidney stones less likely. Some studies have shown that Malic Acid has benefits to those who have dry mouths. Lack of research has created ambiguity when it comes to the long-term effects of Malic Acid. While the ingredient is considered safe most of the time, certain people may experience allergic reactions, headaches, nausea, and increased skin sensitivity (when used as a skincare product).