D-mannose to prevent recurrent urinary tract infections in post-menopausal women.

A Randomized Controlled Trial of D-mannose for the Prophylaxis of Recurrent Urinary Tract Infections in Post-menopausal Women

Not applicable Interventional University of Texas Southwestern Medical Center · NCT06940622

This trial will test whether taking 2 g of D-mannose daily prevents recurrent urinary tract infections in post‑menopausal women.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment90 (estimated)
Ages55 Years to 85 Years
SexFemale
SponsorUniversity of Texas Southwestern Medical Center Academic / other
Drugs / interventionschemotherapy, immunotherapy
Locations1 site (Dallas, Texas)
Trial IDNCT06940622 on ClinicalTrials.gov

What this trial studies

This randomized, double-blind, placebo-controlled trial will enroll 90 post‑menopausal women with a history of recurrent uncomplicated UTIs and randomize them 2:1 to receive 2 g daily D‑mannose or placebo for 12 months. Participants must be UTI-free at entry and will undergo baseline urinary tract evaluation; outcomes include symptomatic UTI recurrence confirmed by urine culture, one-hour D‑mannose test results, and scheduled follow-up visits. The primary efficacy comparison will be at six months with continued follow-up to one year to assess durability of effect. The study follows CONSORT guidelines and uses objective microbiologic and symptom measures to identify responders.

Who should consider this trial

Good fit: Ideal candidates are post‑menopausal women aged 55 or older with documented recurrent uncomplicated UTIs who are currently free of infection and able to attend in‑person follow‑up at the study site.

Not a fit: Patients with complicated UTIs (including need for catheter drainage), structural urinary tract abnormalities, current D‑mannose use without a washout, men, or pre‑menopausal women are unlikely to benefit from this protocol.

Why it matters

Potential benefit: If effective, daily D‑mannose could provide a safe, non‑antibiotic way to reduce UTI recurrences in post‑menopausal women.

How similar studies have performed: One prior randomized trial suggested D‑mannose may reduce UTI recurrence, but confirmatory larger trials are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Female, post-menopausal, age ≥ 55 years old
* Diagnosis of recurrent UTI, defined as ≥ 3 symptomatic culture-proven UTI episodes in 12 months or ≥ 2 in 6 months.
* Currently free from a UTI determined based on absence of symptoms as determined by the UTI symptom assessment questionnaire79 and negative urine culture (\<103 colony forming units per ml of urine).
* Able to attend all follow-up appointments for the study.
* A negative upper and lower urinary tract evaluation, including pelvic examination for pelvic organ prolapse (less than stage 2), measurement of post-void residual (less than 50 ml), and imaging (renal ultrasound and standing voiding cystourethrogram) to exclude kidney stone, hydronephrosis, reflux, or urethral diverticulum.

Exclusion Criteria:

* Current use of D-mannose. Patients willing to stop taking D-mannose will be offered to join the trial after a 4-week wash-out period.
* Complicated UTIs, including need for catheter drainage or intermittent catheterization, neurogenic bladder, bladder augmentation, or urinary diversion.
* Ongoing supplement use (Box 1). Patients willing to stop taking the listed supplements will be offered to join the trial after a 4-week wash-out period.
* Evidence of upper tract infection (pyelonephritis), including temperature higher than 38°C, flank/lumbar pain or tenderness
* Diagnosis of interstitial cystitis or overactive bladder syndrome
* Prophylactic antibiotics started in the last 3 months and unwilling to discontinue, or intention to start in the next 12 months
* Use of Uromune or other vaccine approaches to reduce rUTI
* Participation in a research study involving an investigational product in the past 12 weeks
* Receipt of phage treatment
* History of chronic diarrhea requiring regular therapy
* Inability to swallow or known history of gastrointestinal malabsorption
* History of recurrent vaginal yeast infections
* Systemic disease precluding enrollment in this study (uncontrolled diabetes with HgA1C above 7, ongoing chemotherapy or immunotherapy, renal insufficiency \[creatinine \> 1.5 g/dl\]), mental or cognitive impairment, weight loss diet requiring excessively large amounts of fluid intake, or other health-related specific diet).
* Nursing home resident
* BMI \>40

Box 1 Supplements to avoid

* Multi-Vitamins and Multi-Mineral capsules
* Specific Vitamins or Minerals (e.g., Calcium, Citrical, Calcium Gummies, Vitamin A, D, Niacin, Pyridoxine, Selenium, Vitamin E, B6, Iron, Omega 3, D3, Magnesium, B-Complex, Women's Ultra MultiVitamin, GNC B-Complex, B-12, PreserVision Areds2, Vitamins D, B Pollen)
* Probiotics
* Cranberry Mannose or Cranberry Extract Weight loss products to avoid
* Medifast
* Vitafusion
* OptiVin Products
* Appetite Suppressants
* Keto-Fuel

Where this trial is running

Dallas, Texas

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Recurrent UTIsRecurrent Urinary Tract InfectionsRecurrent Urinary Tract Infections in WomenRecurrent Urinary Tract InfectionCystitis RecurrentCystitis ChronicUTIUTI - Urinary Tract Infection
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.