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Supplement Forms/Alternate Names:

American cranberry, bearberry


Cranberry is a small red berry that is high in Vitamin C. This vitamin helps the body fight illness. Cranberry has been used to prevent bacterial infections. It can be taken as a juice, extract, cooked, or eaten raw. It can also be taken as a pill or powder.


500 milligrams 1 to 2 times daily or one glass 1 to 2 times daily

What Research Shows

Likely Effective

  • Urinary tract infection —likely to prevent infectionC1-C21

May Be Effective

  • Helicobacter pylori infection —may reduce time of infection when used with standard treatmentA1, A2

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

Safety Notes

It is likely safe for most people to take cranberry.


Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse, such as:

  • People with proton pump inhibitors should talk to their doctors before taking cranberry. It may reduce effectiveness.
  • People with stomach ulcers or acid reflex should talk to their doctor before taking cranberry. It may interact with their medicines.
  • People taking blood thinners or medicine to break up blood clots should talk to their doctors before taking large amounts of cranberry. It may increase the risk of bleeding.B1-B3


A. Helicobacter Pylori

A1. Seyyedmajidi M, Ahmad A, et al. Addition of cranberry to proton pump inhibitor-based triple therapy for Helicobacter pylori eradication. J Res Pharm Pract. 2016;5(4):248-251.

A2. Yang-Ou YB, Hu Y, et al. The effect of antioxidants on Helicobacter pylori eradication: A systematic review with meta-analysis. Helicobacter. 2018 Dec;23(6):e12535. Dec;23(6):e12535.

B. Safety

B1. Haber SL, Cauthon KA, et al. Cranberry and warfarin interaction: a case report and review of the literature. Consult Pharm. 2012 Jan;27(1):58-65.

B2. Srinivas NR. Cranberry juice ingestion and clinical drug-drug interaction potentials; review of case studies and perspectives. J Pharm Pharm Sci. 2013;16(2):289-303.

B3. Norwood DA, Parke CK, et al. A Comprehensive Review of Potential Warfarin-Fruit Interactions. J Pharm Pract. 2015 Dec;28(6):561-571.

C. Urinary Tract Infection

C1. Vidlar A, Vostalova J, et al. The effectiveness of dried cranberries (Vaccinium macrocarpon) in men with lower urinary tract symptoms. Br J Nutr. 2010 Oct;104(8):1181-1189.

C2. Barbosa-Cesnik C, Brown MB, et al. Cranberry juice fails to prevent recurrent urinary tract infection: results from a randomized placebo-controlled trial. Clin Infect Dis. 2011 Jan 1;52(1):23-30.

C3. Afshar K, Stothers L, et al. Cranberry juice for the prevention of pediatric urinary tract infection: a randomized controlled trial. J Urol. 2012 Oct;188(4 Suppl):1584-1587.

C4. Salo J, Uhari M, et al. Cranberry juice for the prevention of recurrences of urinary tract infections in children: a randomized placebo-controlled trial. Clin Infect Dis. 2012 Feb 1;54(3):340-346.

C5. Stapleton AE, Dziura J, et al. Recurrent urinary tract infection and urinary Escherichia coli in women ingesting cranberry juice daily: a randomized controlled trial. Mayo Clin Proc. 2012 Feb;87(2):143-50.

C6. Wang CH, Fang CC, et al. Cranberry-containing products for prevention of urinary tract infections in susceptible populations: a systematic review and meta-analysis of randomized controlled trials. Arch Intern Med. 2012;172(13):988-996.

C7. Takahashi S, Hamasuna R, et al. A randomized clinical trial to evaluate the preventive effect of cranberry juice (UR65) for patients with recurrent urinary tract infection. J Infect Chemother. 2013 Feb;19(1):112-117.

C8. Caljouw MA, van den Hout WB, et al. Effectiveness of cranberry capsules to prevent urinary tract infections in vulnerable older persons: a double-blind randomized placebo-controlled trial in long-term care facilities. J Am Geriatr Soc. 2014 Jan;62(1):103-110.

C9. Barnoiu OS, Sequeira-García Del Moral J, et al. American cranberry (proanthocyanidin 120 mg): its value for the prevention of urinary tracts infections after ureteral catheter placement. Actas Urol Esp. 2015;39(2):112-117.

C10. Foxman B, Cronenwett AE, et al. Cranberry juice capsules and urinary tract infection after surgery: results of a randomized trial. Am J Obstet Gynecol. 2015;213(2):194.

C11. Vostalova J, Vidlar A, et al. Are High Proanthocyanidins Key to Cranberry Efficacy in the Prevention of Recurrent Urinary Tract Infection? Phytother Res. 2015;29(10):1559-1567.

C12. Juthani-Mehta M, Van Ness PH, et al. Effect of Cranberry Capsules on Bacteriuria Plus Pyuria Among Older Women in Nursing Homes: A Randomized Clinical Trial. JAMA. 2016 Nov 8;316(18):1879-1887.

C13. Maki KC, Kaspar KL, et al. Consumption of a cranberry juice beverage lowered the number of clinical urinary tract infection episodes in women with a recent history of urinary tract infection. Am J Clin Nutr. 2016;103(6):1434-1442.

C14. Occhipinti A, Germano A, et al. Prevention of Urinary Tract Infection with Oximacro, A Cranberry Extract with a High Content of A-Type Proanthocyanidins: A Pre-Clinical Double-Blind Controlled Study. Urol J. 2016;13(2):2640-2649.

C15. Singh I, Gautam LK, et al. Effect of oral cranberry extract (standardized proanthocyanidin-A) in patients with recurrent UTI by pathogenic E. coli: a randomized placebo-controlled clinical research study. Int Urol Nephrol. 2016;48(9):1379-1386.

C16. Vidlar A, Student V Jr, et al. Cranberry fruit powder (Flowens™) improves lower urinary tract symptoms in men: a double-blind, randomized, placebo-controlled study. World J Urol. 2016;34(3):419-424.

C17. Wan KS, Liu CK, et al. Cranberries for Preventing Recurrent Urinary Tract Infections in Uncircumcised Boys. Altern Ther Health Med. 2016 Nov;22(6):20-23.

C18. Fu Z, Liska D, et al. Cranberry Reduces the Risk of Urinary Tract Infection Recurrence in Otherwise Healthy Women: A Systematic Review and Meta-Analysis. J Nutr. 2017;47(12):2282-2288.

C19. Gunnarsson AK, Gunningberg L, et al. Cranberry juice concentrate does not significantly decrease the incidence of acquired bacteriuria in female hip fracture patients receiving urine catheter: a double-blind randomized trial. Clin Interv Aging. 2017 Jan 13;12:137-143.

C20. Ledda A, Belcaro G, et al. Highly standardized cranberry extract supplementation (Anthocran®) as prophylaxis in young healthy subjects with recurrent urinary tract infections. Eur Rev Med Pharmacol Sci. 2017 Jan;21(2):389-393.

C21. Temiz Z, Cavdar I, et al. The effects of training and the use of cranberry capsule in preventing urinary tract infections after urostomy. Complement Ther Clin Pract. 2018;31:111-117.

Last reviewed February 2020 by EBSCO NAT Review Board Eric Hurwitz, DC