D-mannose is a simple sugar structurally related to glucose. It is absorbed slowly from the gastrointestinal tract, and then a large proportion of it is excreted into the urine.1

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Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.

2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

This supplement has been used in connection with the following health conditions:

Used for Why
1 Star
Urinary Tract Infection
Refer to label instructions
D-Mannose may help treat UTIs by binding to bacteria that would otherwise attach to the urinary tract lining.

Some bacteria that typically cause urinary tract infections can attach themselves to the lining of the urinary tract by binding to molecules of mannose that naturally occur there. Theoretically, if enough D-mannose is present in the urine, it would bind to the bacteria and prevent them from attaching to the urinary tract lining. One animal study has demonstrated this protective effect, but whether it would occur in humans is unknown, and no human research has investigated the effectiveness of oral D-mannose for the prevention or treatment of urinary tract infections.

How It Works

How to Use It

Some doctors report that D-mannose might help prevent or treat urinary tract infections caused by E. coli and recommend 1 teaspoon (5 ml) dissolved in water or juice every two to three hours while awake.2

Where to Find It

D-Mannose is in many fruits, including Peaches, apples, oranges, cranberries, and blueberries.

Possible Deficiencies

As D-mannose is not an essential nutrient, except in certain rare genetic disorders people produce sufficient amounts to provide for the bodies' needs.


Interactions with Supplements, Foods, & Other Compounds

At the time of writing, there were no well-known supplement or food interactions with this supplement.

Interactions with Medicines

As of the last update, we found no reported interactions between this supplement and medicines. It is possible that unknown interactions exist. If you take medication, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.

Side Effects

Side Effects

Test tube and animal studies suggest that consuming large amounts of mannose might lead to birth defects,3 , 4 although the amounts of mannose used on those studies were far greater than the amounts a person would ingest from food or from a supplement to treat a urinary tract infection. Nonetheless, until more is known, pregnant women should use supplemental mannose with caution.


1. Herman RH. Mannose metabolism I. Am J Clin Nutr 1971;24:488-98 [review].

2. Wright JV, Lenard L. D-Mannose & Bladder Infection:The Natural Alternative to Antibiotics. Auburn, WA: Dragon Art, 2001:17.

3. Freinkel N, Lewis NJ, Akazawa S, Roth SI, Gorman L. The honeybee syndrome: implications of the teratogenicity of mannose in rat-embryo culture. N Engl J Med 1984;310:223-30.

4. Buchanan T, Freinkel N, Lewis NJ, et al. Fuel-mediated teratogenesis. Use of D-mannose to modify organogenesis in the rat embryo in vivo. J Clin Invest 1985;75:1927-34.