Fever-Tree’s Naturally Light Tonic Water combines citrus, aromatic botanicals, soft spring water and a small amount of fruit sugar to create a delicious, crisp taste balanced by the bitterness of natural quinine. With 58% fewer calories, this is the world’s first all natural, low calorie tonic water.Naturally Sourced IngredientsMexican Bitter Orange, African Marigold and Natural Quinine from the Congo.