D-Mannose

D-Mannose · Mannose · Seminose

Snapshot

Indications	Contraindications
Recurrent UTI prevention^{1, 2} Acute UTI symptoms^1–4 Acute cystitis support^5–7 Postoperative urinary symptoms⁸ UTI in multiple sclerosis^1–4	Fever or blood in urine⁹ Pregnancy or breastfeeding⁹ History of kidney stones¹⁰

D-mannose is a simple sugar found in fruits and marketed as a supplement to lower the risk of urinary tract infection (UTI).¹¹ Once excreted in urine, it is thought to keep Escherichia coli from attaching to the urinary lining¹¹. Women with recurrent UTI who want to limit antibiotic exposure are the typical users, mainly for prevention¹. It is also used for symptom relief during acute cystitis, where the trials are small and often test combination products^{6, 7, 12}.

Evidence on recurrence is split. Earlier meta-analyses found fewer recurrences than with placebo, while a Cochrane review rated the evidence very low certainty. A 2024 placebo-controlled trial in United Kingdom primary care and a 2025 meta-analysis of randomized controlled trials found no reduction in recurrence^{3, 4}. A 2024 before-and-after study of a care bundle that included D-mannose reported fewer infections and less antibiotic use in women with recurrent UTI; no controlled trial isolates D-mannose within a bundle. United States label records show 396 products listing D-mannose, mostly capsules and powders; see Form comparison.

Health Canada labels on licensed products ask for a practitioner's advice before use with fever, painful urination, spasms, or blood in urine⁹. They also ask for practitioner advice before use in pregnancy or breastfeeding⁹.

Last updated October 15, 2026. Read how we make monographs.

In the full monograph

43 sources, 27 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources