Uva ursi
In women with acute urinary tract infections, uva ursi did not ease symptoms more than placebo in one trial. In another it left more symptoms than a single antibiotic dose and cut antibiotic courses, and pyelonephritis occurred in 8 women against 2. Arbutin is excreted as hydroquinone, and one case of eye damage after 3 years of use is published.
- Status
- Dietary supplement in the US. Not approved by the FDA as a drug for any use.
- Also called
- bearberry, bearberry leaf, Arctostaphylos uva-ursi, uvae ursi folium, arbutin, kinnikinnick
- Taken for
- UTI, urinary tract infections, bladder infections, cystitis, bladder health, urinary tract health
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Shown to help0
No benefit shown in research yet.
Reported risks3
- LimitedOne trial found 8 kidney infections on uva ursi against 2 on an antibiotic in women with urinary tract infection, not a significant difference.
- LimitedLimited evidence: about two thirds of the arbutin dose leaves in urine as hydroquinone, estimated below the permitted daily exposure. No long-term human study was found.
- LimitedCase reports: a woman who took uva ursi for 3 years developed bull's-eye maculopathy in both eyes with reduced vision.
What people take it for, and what was found
Not shown to help1
Treating an acute urinary tract infection
Limited evidence: two trials in women with urinary tract infection found no symptom change against placebo, and more symptoms than a single antibiotic dose.
The numbers and sources
- Effect
- In 382 women with suspected lower UTI who all held a delayed antibiotic prescription, uva ursi extract did not change frequency symptoms on days 2 to 4 against placebo (difference -0.06, 95% CI -0.33 to 0.21). Antibiotic use was 39.9% on uva ursi and 47.4% on placebo, a difference that was not significant (OR 0.59, 95% CI 0.22 to 1.58) [1]. In 398 women with uncomplicated UTI, uva ursi for 5 days led to 63.6% fewer antibiotic courses than a single 3 g dose of fosfomycin, and a symptom burden 136.5% of the fosfomycin group's, which failed the trial's non-inferiority margin [2].
- Population
- Women aged 18 to 70 in UK primary care [1]. Adult women in 42 German family practices [2].
- Sources
- [1], [2]
- Caveats
- Two trials. Trial [2] compared uva ursi with an antibiotic, not with placebo.
Doses studied
The German trial used 105 mg tablets, 2 tablets three times a day for 5 days [2]. A toxicology review assessed a daily dose of 420 mg of hydroquinone derivatives, calculated as anhydrous arbutin [3].
Risks
Reported risks2
Kidney infection and symptoms compared with an antibiotic
One trial found 8 kidney infections on uva ursi against 2 on an antibiotic in women with urinary tract infection, not a significant difference.
The numbers and sources
- Effect
- Eight women developed pyelonephritis on uva ursi against 2 on fosfomycin (mean difference 2.8, 95% CI 0.2 to 5.9, p 0.067). Adverse events were otherwise similar between groups [2]. In the placebo-controlled trial, no upper tract infections were recorded [1].
- Population
- Women with uncomplicated UTI [1][2].
- Sources
- [2], [1]
- Caveats
- The pyelonephritis difference did not reach statistical significance in one trial [2].
Eye damage case report
Case reports: a woman who took uva ursi for 3 years developed bull's-eye maculopathy in both eyes with reduced vision.
Mixed results1
Hydroquinone exposure
Limited evidence: about two thirds of the arbutin dose leaves in urine as hydroquinone, estimated below the permitted daily exposure. No long-term human study was found.
The numbers and sources
- Effect
- In 16 healthy volunteers given a single dose of bearberry leaf extract, 64.8% to 66.7% of the arbutin dose was excreted in urine as hydroquinone and its conjugates [4]. A review of published and unpublished data estimated that the 420 mg daily dose releases free hydroquinone in urine at up to 11 µg/kg body weight a day, against an estimated permitted daily exposure of 100 µg/kg. It found no direct human data linking free hydroquinone to convulsions, liver or kidney toxicity, or tumors [3].
- Population
- Healthy adults [4]. Experimental and human studies [3].
- Sources
- [4], [3]
- Caveats
- The permitted exposure figure was derived from an experimental no-effect level, not from human outcomes [3]. No long-term human study of hydroquinone from uva ursi was located.
Claims tested and not found
- That uva ursi relieves the symptoms of an acute bladder infection. In 382 women, frequency symptoms on days 2 to 4 did not differ from placebo [1].
Sources
- Moore M, Trill J, Simpson C, et al. Uva-ursi extract and ibuprofen as alternative treatments for uncomplicated urinary tract infection in women (ATAFUTI): a factorial randomized trial. Clinical Microbiology and Infection. 2019. https://doi.org/10.1016/j.cmi.2019.01.011
- Gágyor I, Hummers E, Schmiemann G, et al. Herbal treatment with uva ursi extract versus fosfomycin in women with uncomplicated urinary tract infection in primary care: a randomized controlled trial. Clinical Microbiology and Infection. 2021. https://doi.org/10.1016/j.cmi.2021.05.032
- de Arriba SG, Naser B, Nolte KU. Risk assessment of free hydroquinone derived from Arctostaphylos Uva-ursi folium herbal preparations. International Journal of Toxicology. 2013. https://doi.org/10.1177/1091581813507721
- Schindler G, Patzak U, Brinkhaus B, et al. Urinary excretion and metabolism of arbutin after oral administration of Arctostaphylos uvae ursi extract as film-coated tablets and aqueous solution in healthy humans. The Journal of Clinical Pharmacology. 2002. https://doi.org/10.1177/009127002401102740
- Wang L, Del Priore LV. Bull's-eye maculopathy secondary to herbal toxicity from uva ursi. American Journal of Ophthalmology. 2004. https://doi.org/10.1016/j.ajo.2004.01.004