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Women

D-Mannose

Simple sugar studied for preventing recurrent UTIs by blocking E. coli adhesion in women with frequent infections.

D-Mannose
44
score
C
evidence
Safe
risk

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Quick Take

Worth considering if you have recurrent UTIs; otherwise low return for general health.

D-mannose is a naturally occurring simple sugar found in small amounts in cranberries, apples and oranges. It is absorbed poorly and much of it is excreted unchanged in urine. There it can bind the FimH adhesin on uropathogenic E. coli and reduce attachment to bladder cells. The main evidence-backed use is preventing recurrent UTIs in women with repeated uncomplicated infections; evidence for treating an active UTI is much weaker. Women with frequent UTIs who want a non-antibiotic prevention option are the most likely to consider it.

Potential benefits

01
May reduce recurrent UTIs

Protocol

Amount
2 g
Frequency
Once daily
When
Any time of day — take with water; consistency matters more than timing.

Onset Time

4-8 weeks for prevention benefit; acute treatment not established

Who Should Consider

Women with recurrent UTIs
Postmenopausal women with rUTIs
Women wanting antibiotic-sparing prevention

How It Works

Free D-mannose in urine competes with mannose-containing receptors on the bladder surface, blocking FimH-mediated adhesion by uropathogenic E. coli so bacteria are flushed out during urination. It does not directly kill bacteria or meaningfully change urine pH.

Updated 5/19/2026

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