Quinine has a bitter taste. It was first added to drinks like Bitter Lemon and Tonic Water Quinine was added to have some protection against Malaria. In China, it is sometimes added to drugs against the Common cold. Quinine is also often used to add a bitter taste to food. Usually this has to be declared though. Quinine can also stimulate the muscles of the uterus. For this reason, pregnant women should not take too much of it. Sometimes it is used in combination with Heroin.