Don't Down Your Meds With Juice

Popping pills to stifle sniffles? If you’re taking Allegra, don’t down it with juice: It decreases its effectiveness.

When researchers took blood samples from people who swallowed the antihistamine with 10 ounces of grapefruit juice, the drug’s presence in the bloodstream decreased by about 50 percent. Naringin, a component in grapefruit juice (apple juice and OJ have a similar compound), inhibits activity of the protein that helps your body absorb the drug, says David Bailey, Ph.D., of the University of Western Ontario.

Other allergy meds may pose the same problem, so allow four hours before or after taking them to get your juice fix.