Remedy · supplement
D-mannose
Also: mannose
A popular sugar supplement for UTI prevention that failed its largest, most rigorous trial.
Evidence by condition
Each grade reflects the research for D-mannose and that condition specifically.
- DRecurrent urinary tract infection
Despite a plausible mechanism and popularity, the largest double-blind trial to date (MERIT, 598 women) found no significant benefit over placebo and concluded it should not be recommended for prevention.
1 citation
- d-Mannose for Prevention of Recurrent Urinary Tract Infection Among Women: A Randomized Clinical Trial Randomized trial 2024 · n=598 · JAMA Internal Medicine · DOI 10.1001/jamainternmed.2024.0264
- d-Mannose for Prevention of Recurrent Urinary Tract Infection Among Women: A Randomized Clinical Trial
D-mannose is thought to stop E. coli sticking to the bladder wall, and small studies once looked promising — but the large, well-designed MERIT trial found it no better than placebo. On current best evidence it should not be relied on to prevent UTIs.