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ingestible · for uti prevention

D-Mannose

Reviewed by the Nimbera editorial team · Last updated May 2026

Kranjcec et al. (2014, PMID 23633128) 3-arm RCT (n=308 women) found D-mannose 2 g/day for 6 months reduced UTI recurrence to 14.6% vs 60.8% in no-prophylaxis controls. Recurrence was comparable to nitrofurantoin (20.4%) but with significantly fewer side effects. Note: a 2024 JAMA Internal Medicine RCT (PMID 38587819) found no significant benefit in a broader population.$15-$30 per month

How to use

Take 2 g of D-mannose powder or capsules dissolved in water once daily as a prevention dose. Some protocols use a higher 1.5 g twice-daily dose at the first sign of symptoms.

How it works

D-mannose is a simple sugar that binds to type-1 fimbriae on E. coli, competing with uroepithelial mannose receptors. E. coli bound to free D-mannose in the urine are flushed out rather than adhering to the bladder wall.

Where to buy

Health food stores, pharmacies, and online retailers. Available as powder or capsules under brands such as Now Foods, Solaray, and Now D-Mannose.

Typical cost: $15-$30 per month

Safety notes

Not effective for non-E.-coli UTIs (which account for roughly 10-20% of cases). Not a treatment for active infection. Diabetics should monitor blood glucose as D-mannose is a sugar, though it is minimally metabolised. Evidence in men is very limited.

Drug & supplement interactions

  • Always tell your doctor or pharmacist about any supplements you take.
  • Interactions can occur with prescription medications, blood thinners, and immunosuppressants.
  • Herbal remedies can affect how the body absorbs or metabolises drugs.
  • Check drugs.com interactions checker before starting.

Clinical source

Kranjcec B et al., D-mannose powder for prophylaxis of recurrent UTIs in women: a randomized clinical trial, World J Urol, 2014

This information is compiled from primary clinical literature and is for informational purposes only. It is not a substitute for professional medical advice. Read our full disclaimer.