D-Mannose for UTI Prevention

Can it help prevent urinary tract infections?

Woman suffering from abdominal pain
BSIP/UIG/Getty Images

D-mannose is a type of sugar found in a number of fruits (including cranberries, black and red currants, and peaches). Also available in dietary supplement form, D-mannose is typically touted as a natural remedy for fending off urinary tract infections (UTI) and bladder infections.

Why Is D-Mannose Sometimes Used for UTIs?

D-mannose is thought to keep bacteria from sticking to the walls of the urinary tract, which is why it's sometimes taken as a home remedy to prevent and treat urinary tract infections.

In addition, D-mannose is sometimes used for carbohydrate-deficient glycoprotein syndrome, a genetic disorder that interferes with the body's ability to properly break down and produce mannose (a sugar molecule that plays a key role in metabolism). Proponents claim that the use of D-mannose can help improve liver function, regulate blood sugar levels, and protect against blood clotting in people with this syndrome.

The Benefits of D-Mannose - Can It Really Help?

There's a lack of high-quality clinical trials (the kind of research you want to see to put stock in a treatment) showing that D-mannose can help with UTIs. However, preliminary studies suggest that the supplement could be worth exploring: 

In a laboratory study published in the journal PLoS One in 2008, for instance, scientists demonstrated that D-mannose can help stop E. coli (the type of bacteria responsible for the vast majority of UTIs) from sticking to cells found in the urinary tract.

For a study published in World Journal of Urology in 2014, 98 women with a history of recurrent UTIs took D-mannose, the antibiotic nitrofurantoin, or nothing for six months. Women taking the D-mannose or nitrofurantoin had a lower risk of recurrent UTIs. 

Possible Side Effects

Little is known about the safety of long-term or high-dose use of D-mannose supplements.

However, D-mannose supplements can trigger a number of side effects such as bloating. When taken in excessive doses, there's some concern that D-mannose may lead to kidney damage.

Since D-mannose may alter your blood sugar levels, it's crucial for diabetes patients to take caution when using D-mannose supplements. Pregnant and nursing women and children shouldn't take D-mannose.

It's also worth noting that self-treating any condition with D-mannose supplements, and avoiding or delaying standard care, may have serious health consequences. 

Some Final Thoughts

It may be tempting to want to try D-mannose to self-treat a UTI, but here's why you shouldn't: if a UTI isn't completely eradicated, the infection may spread (to the kidneys) even though the symptoms may appear to improve. Also, there are some concerns about the side effects that may result from taking high doses of the supplement.

f you're still thinking of trying it (or are considering taking it for preventative purposes), be sure to talk with your doctor first to weigh the pros and cons and discuss whether it's appropriate for you.

If you're seeking a natural remedy for the prevention of UTIs, several other dietary supplements may be of some benefit.

For instance, some research suggests that drinking cranberry juice might help decrease the incidence of urinary tract infections among people prone to this condition. 

Besides D-mannose, certain compounds found in cranberries (including proanthocyanins, a type of antioxidant) may help prevent UTIs by keeping bacteria from adhering to the walls of the urinary tract. If using cranberry juice, opt for the unsweetened variety to limit your sugar intake.

For more help in fighting off urinary tract infections, make sure to drink plenty of water on a regular basis. By doing so, you'll increase the likelihood that bacteria will be flushed from your urinary tract before infection sets in.


Kranjčec B, Papeš D, Altarac S. D-mannose powder for prophylaxis of recurrent urinary tract infections in women: a randomized clinical trial. World J Urol. 2014 Feb;32(1):79-84. doi: 10.1007/s00345-013-1091-6. 

Wellens A, Garofalo C, Nguyen H, et al. Intervening with urinary tract infections using anti-adhesives based on the crystal structure of the FimH-oligomannose-3 complex. PLoS One. 2008 Apr 30;3(4):e2040.

Disclaimer: The information contained on this site is intended for educational purposes only and is not a substitute for advice, diagnosis or treatment by a licensed physician. It is not meant to cover all possible precautions, drug interactions, circumstances or adverse effects. You should seek prompt medical care for any health issues and consult your doctor before using alternative medicine or making a change to your regimen.

Continue Reading