Cranberry products like juice, capsules or tablets may help to prevent a urinary tract infection (UTI) in some people, but studies have not shown it can help to treat an active UTI.

A 2023 Cochrane review of over 50 randomized controlled trials (8857 participants) found that taking cranberry (as concentrated liquid, juice, capsules or tablets) reduced the risk of having repeat symptoms for a urinary tract infection (UTI) in certain populations.

• In women by more than 25% (relative risk [RR]=0.74), and by more than 50% in children (RR 0.46) and those susceptible to UTIs following interventions (RR 0.47). Few side effects were reported (primarily stomach pain).
• The evidence did not support cranberry use in the elderly, patients with neuromuscular bladder emptying problems, or pregnant women. The researchers could not prove if cranberry products are more or less effective than antibiotics or probiotics in preventing further UTIs.
• This study did not identify the best cranberry dose or the best way to consume cranberries. Authors concluded more well-designed randomized controlled studies are need to clarify who would benefit from cranberry for UTI prevention.

How do cranberries prevent UTIs?

Cranberries contain proanthocyanidins, compounds thought to stop infection-causing bacteria like Escherichia coli (E. coli) from taking up residence in the lining of the urinary tract.

Cranberry juice is considered to be an effective prevention for urinary tract infection (UTI’s) for some people. But cranberry juice cannot treat an active UTI or bladder infection; for that, you'll need to see a doctor. In fact, you may need an antibiotic medication treatment.

Symptoms of a UTI

• pain or burning while urinating
• lower stomach or pelvic cramping
• frequent need to urinate
• blood in your urine
• feeling an urgent need to urinate even though your bladder is empty.

Is cranberry juice for a UTI?

If you drink a moderate amount of cranberry juice and can tolerate it, there is usually no harm. Be sure to also drink added water throughout the day. Other options for women, like urinating after sex may help too. But remember - cranberry juice may be loaded with sugar and carbohydrates, and can contribute to tooth decay, weight gain and diarrhea.

Cranberry may have a drug interaction with blood thinner like warfarin. If you take a blood thinner, speak to your doctor before consuming a cranberry product. Using these products together may cause you to bleed more easily and you may need more frequent INR testing.

Cranberry is often sold as an herbal supplement online. These products are not regulated by the FDA and may contain toxins or other unknown substances. Herbal or health supplements should be purchased from a reliable source to minimize the risk of contamination. Avoid buying online from unknown retailers. Check with your local pharmacist for reliable brands.

Bottom Line

• To help prevent a urinary tract infection (UTI), doctors primarily recommend that women drink plenty of water and urinate as needed. It is recommended that women with frequent UTIs drink at least 2 liters of water each day.
• While cranberry juice is claimed to have antiseptic qualities, it’s important to get an antibiotic prescription quickly if you do indeed have a UTI. See your doctor if you have UTI symptoms, such as pain or burning while urinating, lower stomach cramping, frequent urination, blood in your urine, or urgent need to urinate even though your bladder is empty.
• There is usually no harm in drinking moderate amounts of cranberry juice, but it may not always help prevent a UTI. Harms include dental cavities, weight gain or diarrhea. There is the potential for a drug interaction with warfarin and similar blood thinners. Cranberry juice has not been shown to help treat an active UTI or bladder infection.

This is not all the information you need to know about cranberry and UTIs for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.