Some drugs enter the blood stream much more effectively when taken with grapefruit juice, as metabolism is inhibited. http://www.powernetdesign.com/grapefruit/general/GJDIsummary.pdf Many people say that grapefruit (and other citrus) juice reacts with creatine forming useless creatinine, thus they should not be mixed. Some people recommend it. They argue that the pH of stomach acid (HCl) is much lower than that of grapefruit juice (the citric acid is highly diluted), and breakdown due to the juice would be insignificant. Have any of you taken creatine with grapefruit juice? If so what were your results, i.e. did you notice a difference?