Taste-changing tablets harness the unique properties of the miracle berry, which contains the active glycoprotein called miraculin. When you consume these tablets, miraculin binds to the sweet receptors on your taste buds. Under normal conditions, miraculin blocks these receptors, but in the presence of acidic (sour) foods, it undergoes a conformational change that activates the sweet receptors, causing sour foods to taste sweet. This effect can last from 30 minutes to two hours, depending on the individual and the amount consumed.