Tuesday, December 29, 2009

Medicinal Herbs: Uva Ursi

Uva ursi


Uva ursi (Arctostaphylos uva ursi), also known as bearberry because bears like eating the fruit, has been used medicinally since the 2nd century. Native Americans used it as a remedy for urinary tract infections. In fact, until the discovery of sulfa drugs and antibiotics, uva ursi was a common treatment for such bladder and related infections. Through modern-day scientific research in test tubes and animals, researchers have discovered that uva ursi's antibacterial properties, which can fight infection, are due to several chemicals, including arbutin and hydroquinone. The herb also contains tannins that have astringent effects, helping to shrink and tighten mucous membranes in the body. That, in turn, helps reduce inflammation and fight infection.

Today, uva ursi is sometimes used to treat urinary tract infections and cystitis (bladder inflammation). Researchers believe the herb is most effective when a person's urine is alkaline since acid destroys its antibacterial effect. However, more research is needed to determine if uva ursi is effective in humans.

In addition, uva ursi can be toxic: Hydroquinone can cause serious liver damage. Conventional medications that have fewer risks are available to treat urinary tract infections.

Plant Description

Uva ursi is a trailing evergreen shrub that produces red berries and flourishes in alpine forests in many regions, including North America, Europe, the Iberian Peninsula, Siberia, and the Himalayas. It grows slowly but succeeds in places where other plants cannot, such as the walls of canyons. It has short, creeping, red-brown branches and pink or white bell-shaped flowers that bloom in the summer, followed by clusters of berries. Bears are said to be fond of the shiny, bright red or pink fruit, which is edible but sour tasting.

Parts Used

Only the leaves -- not the berries -- are used in medicinal preparations.

Available Forms

Uva ursi is commercially available as crushed leaf or powder preparations.

How to Take It


Do not give uva ursi to children.


Because uva ursi can be toxic, talk to your doctor before taking it. Recommended adult doses are:

  • Dried herb (available in capsules): 2 - 4 g per day, standardized to 400 - 800 mg of arbutin
  • Tea: Soak 3 g of dried leaves in 5 oz. of water for 12 hours. Strain and drink hot or cold 3 - 4 times per day.

Uva ursi should not be taken for more than 5 days at a time. (See "Precautions" section.) Do not take with vitamin C or orange juice.


The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.

Because uva ursi requires an alkaline urine to work as an antibiotic, you should avoid eating foods that contribute to forming acidic urine.

One of the chemicals in uva ursi, hydroquinone, can be very toxic to the liver. Uva ursi should be taken only for short periods (no longer than 5 days) under a doctor's supervision, and should not be repeated more than 5 times in 1 year. Do not exceed recommended doses.

Reported side effects are generally mild and include nausea and vomiting, irritability, and insomnia.

Women who are pregnant or breastfeeding, or people with high blood pressure, should not take uva ursi.

Possible Interactions

If you are currently being treated with any of the following medications, you should not use uva ursi without first talking to your health care provider.

Drugs and supplements that make urine more acidic -- These include vitamin C, cranberry juice, orange juice, and other citrus fruits and juices.

Nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids -- Animal studies conducted in Japan suggest uva ursi may increase the anti-inflammatory effects of these drugs, although it isn't known whether the herb would have that effect in people.

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