Question: Do cranberry juice or cranberry supplements prevent urinary tract infections (UTIs)?
Answer: At this time, there is no data to support the effectiveness of cranberries to prevent UTIs. Cranberries may act by preventing bacteria from sticking to the urinary tract walls, but there is not enough evidence to suggest this will prevent UTI.
Cranberry juice or supplements don’t treat urinary tract infections once they’ve started. If you still wish to try Cranberry products for prevention of UTIs, they are not likely to cause serious side effects, although upset stomach or heartburn may occur. If you take warfarin (Coumadin) you should talk to your doctor before taking a cranberry product.