Bearberry (uva ursi)

What is bearberry?

Bearberry (Arctostaphylos uva-ursi), often called uva ursi, is a low evergreen shrub that grows across northern North America, Europe and Asia. Its leathery leaves have been used for centuries as a remedy for bladder and urinary complaints, and they appear in herbal teas, tinctures and capsules.

The leaves contain arbutin, a compound that the body breaks down into hydroquinone. Hydroquinone has antibacterial properties, and in traditional theory it acts as a urinary antiseptic once excreted in the urine. Hydroquinone is also the reason for most safety concerns about the herb.

What the research says

High-quality clinical trials of bearberry for urinary tract infections are scarce. Much of its standing comes from traditional use and European herbal monographs that approve it for short-term use in mild lower urinary tract complaints, rather than from large randomized trials.

On safety, a 2013 risk assessment in the International Journal of Toxicology reviewed published and unpublished data on arbutin and hydroquinone. The authors estimated that a recommended daily dose of bearberry leaf extract releases free hydroquinone in urine at levels below an estimated safe threshold, found no direct human evidence of liver, kidney or cancer-promoting effects at those doses, and concluded it is a safe option under recommended conditions. Readers should know that the lead authors were affiliated with a European herbal medicine manufacturer, and that the conclusion is tied to recommended, short-term use.

The NIH LactMed database notes that there are no data on uva ursi in breast milk and advises that it should generally be avoided during breastfeeding because of the lack of data and its potential toxicity.

How it’s used in supplements

Traditionally, bearberry is used for short courses, typically up to about a week, and not more than a few times a year. That traditional pattern is quite different from a once-daily capsule meant to be taken every day for months, as with FemiCore.

Because bearberry appears inside a proprietary blend in FemiCore, the dose is unknown. It may be small. Even so, the combination of an undisclosed amount and indefinite daily use is not how this herb has traditionally been used or evaluated. Avoid it during pregnancy and breastfeeding, in children, and if you have liver or kidney disease. Anyone with symptoms of a urinary infection should see a clinician, since untreated UTIs can spread to the kidneys.