American Dental Association, June 18, 2012 – Grapefruit juice can be part of a healthful dietâ€”most of the time. It has vitamin C and potassium, substances your body needs to work properly.
But it isnâ€™t good for you when it affects the way your medicines work. Grapefruit juice and fresh grapefruit can interfere with the action of some prescription drugs, as well as a few nonprescription drugs.
For some medications, prescription AND non-prescription, â€œthe juice increases the absorption of the drug into the bloodstreamâ€. â€œWhen there is a higher concentration of a drug, you tend to have more adverse events.â€ This caution does not apply to injectable medications.