Plant Part Used



Cranberry fruit juice has been recommended for many years for the treatment of urinary tract infections (UTIs). Recent scientific research lends credence to this folk remedy. (1) , (2) In the United States, UTIs account for a significant number of the bacterial infections that are reported each year. What’s more, one of every five women in the U.S. will suffer from a UTI at some time in her life. Although these infections are not usually life threatening or even a significant health risk for most individuals, there is increasing concern over bacterial resistance to antibiotics that treat UTIs and other infections. Therefore, cranberry could, in some cases, serve as a natural and much-needed complement to conventional antibiotics.

Interactions and Depletions


Dosage Info

Dosage Range

300-400mg (standardized extract), 2 times a day.

Most Common Dosage

300mg (standardized extract), 2 times a day.

Dosage of cranberry juice in preventing and treating urinary tract infections (UTI) in individuals has ranged from 5-20oz administered daily (6oz juice = 90gm fresh fruit), with one study having results with 4-6oz of juice daily for 7 weeks. (3) An active UTI requires more juice than the prevention dose. Also, cranberry juice concentrate capsules are available and have been used in the management of UTI. One 300mg capsule twice daily, either 1 hour before meals or 2 hours after a meal, is recommended. Drink plenty of filtered or bottled water throughout the day. Most studies focus on using cranberry juice cocktail in treating UTI. However, cranberry juice cocktails contain added sugar and may be diluted by other juices. While cranberry juice cocktail is effective in reducing the frequency and severity of UTI, the use of 100% cranberry juice is recommended.


[span class=doc]Standardization represents the complete body of information and controls that serve to enhance the batch to batch consistency of a botanical product, including but not limited to the presence of a marker compound at a defined level or within a defined range.[/span]

The most current available medical and scientific literature indicates that this dietary supplement should be standardized to 11-12% quinic acid per dose; one can also use freeze dried berries or juice concentrate.

Reported Uses

As mentioned, cranberry has chiefly been used to treat and prevent urinary tract infections. Scientists believe that certain components of cranberry actually prevent the bacteria that usually causes UTIs, E. coli, from adhering to the walls of the bladder and colonizing there. (4)

Cranberry has also been used to prevent kidney stones, as well as to remove unwanted toxins from the body. (5)

Cranberry juice may increase plasma antioxidant levels reducing the risk of heart disease. (6) , (7)

Toxicities & Precautions


[span class=alert]Be sure to tell your pharmacist, doctor, or other health care providers about any dietary supplements you are taking. There may be a potential for interactions or side effects.[/span]


This dietary supplement is considered safe when used in accordance with proper dosing guidelines.

Health Conditions

If you have ever had kidney stones talk to your doctor before taking this dietary supplement. (8)

Side Effects

Side effects are possible with any dietary supplement. This dietary supplement may cause diarrhea and stomach upset if large doses are taken. (9) Tell your doctor if these side effects become severe or do not go away.

Pregnancy/ Breast Feeding

To date, the medical literature has not reported any adverse effects related to fetal development during pregnancy or to infants who are breast-fed. Yet little is known about the use of this dietary supplement while pregnant or breast-feeding. Therefore, it is recommended that you inform your healthcare practitioner of any dietary supplements you are using while pregnant or breast-feeding.

Age Limitations

To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Since young children may have undiagnosed allergies or medical conditions, this dietary supplement should not be used in children under 10 years of age unless recommended by a physician.


  1. View Abstract: Lynch DM. Cranberry for prevention of urinary tract infections. Am Fam Physician. 2004 Dec 1;70(11):2175-7.
  2. View Abstract: Jepson RG. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2004;(2):CD001321.
  3. Gibson L, Pike L, et al. Effectiveness of Cranberry Juice in Preventing Urinary Tract Infections in Long-term Care Facility Patients. J Naturopathic Med. 1991;2:45-47.
  4. View Abstract: Zafriri D, et al. Inhibitory Activity of Cranberry Juice on Adherence of Type 1 and Type P Fimbriated Escherichia coli to Eucaryotic Cells. Antimicrob Agents Chemother. 1989;33(1):92-98.
  5. Leung A, et al. Encyclopedia of Common Natural Ingredients Used in Foods, Drugs, and Cosmetcs. New York: Wiley-Interscience Publication; 1996:50-53.
  6. View Abstract: Vinson, JA, Kharrat HA, Samman N. Single-dose and supplementation studies with cranberry juice relevant to its role in heart disease as an antioxidant. American Chemical Society, New Orleans. Mar2003.
  7. View Abstract: Yan X, Murphy BT, Hammond GB, Vinson JA, Neto CC. Antioxidant activities and antitumor screening of extracts from cranberry fruit (Vaccinium macrocarpon). J Agric Food Chem. Oct2002;50(21):5844-9.
  8. View Abstract: Terris MK, Issa MM, Tacker JR. Dietary supplementation with cranberry concentrate tablets may increase the risk of nephrolithiasis. Urology. Jan2001;57(1):26-9.
  9. Behrman: Nelson Textbook of Pediatrics, 16th ed. W B Saunders Company; 2000:2304.