D-mannose is a naturally occurring sugar that is thought to prevent the bacterial colonization of the urinary tract. The research examining whether this sugar supplement can reduce the recurrence of UTIs has been promising. In a meta-analysis of two small clinical trials, taking 2 grams of D-mannose powder daily for up to 6 months reduced the risk of recurrent UTI compared to taking placebo.[1] However, D-mannose has not been shown to be as effective as antibiotics like nitrofurantoin for preventing UTIs.[1]
What’s the story with D-mannose for UTIs?
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•Last Updated: May 16, 2025
D-mannose is a naturally occurring sugar that may help prevent bacterial colonization in the urinary tract, and research indicates that it can reduce the recurrence of urinary tract infections (UTIs) when taken daily. However, it is not as effective as antibiotics like nitrofurantoin for preventing UTIs.