A Trial of D-mannose for the Prophylaxis of Recurrent Urinary Tract Infections

What this trial studies

A randomized, double-blind, placebo-controlled, 12-month study to determine the effectiveness of D-mannose (2g daily) supplementation in rUTI (recurrent urinary tract infection) prevention in post-menopausal women.

Conditions in scope

• Recurrent UTIs
• Recurrent Urinary Tract Infections
• Recurrent Urinary Tract Infections in Women
• Recurrent Urinary Tract Infection
• Cystitis Recurrent
• Cystitis Chronic
• UTI
• UTI - Urinary Tract Infection

Interventions

• D-Mannose (Dietary Supplement) — D-mannose (2g, i.e., 4 x 500mg capsules) daily for 12 months.
• Placebo (Dietary Supplement) — Placebo daily for 12 months.

Who can join

Women only · Ages 55 Years to 85 Years

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

Eligibility wording paraphrased from the public record. View the full criteria on ClinicalTrials.gov before contacting a site.

Where it’s happening

Status & timeline

• Overall status: Recruiting
• Study type: Interventional
• Phase: N/A
• Start date: 2025-08-01
• Primary completion: 2029-09-30
• Last update posted: 2025-09-22
• First posted: 2025-04-23

Sponsor & contact

Lead sponsor: University of Texas Southwestern Medical Center (Other)

For trial site contact information, use the official record at ClinicalTrials.gov. Contact details change frequently and the public record is the source of truth.

Outcome measures

Primary outcomes

• Failure rate (Through study completion, an average of 5 years)
  To determine whether prophylaxis with D-mannose reduces the incidence of UTI episodes compared to placebo. "Failure rate," defined as having 2 UTIs in 6 months or 3 in one year.

Related ClearedRx care

If you’re reading this trial because you have menopause symptoms now, you don’t have to wait for a trial to access evidence-based care. ClearedRx prescribes the same FDA-approved and compounded HRT products that have been studied in trials like this one for decades.