Grapefruit inhibits the ability of the body to break down some prescriptions drugs, which can increase the concentration of those medications in the body. There isn't much information out there about how long the effect of grapefruit juice lasts after it has been consumed. However, we do know that taking certain prescription drugs and grapefruit at the same time is a bad idea. (From the article below) "For example, simvastatin, when taken with about a 7-ounce glass of grapefruit juice once a day for three days, produced a 330% greater concentration of the drug compared to taking it with water"
Common prescription drugs that interact with grapefruit in this manner include:
This is NOT an exhaustive list. Additionally, grapefruit only has this effect on drugs that are taken orally.
Dr. Dielle Raymond, ND