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  • Status:: Closed

Women aged 18 or over who have had at least two UTIs in the last six months or three in the last year will be invited to take part. Eligible patients will be randomly assigned to receive either D-mannose powder or a placebo powder to be taken for 6 months.


Urinary tract infections (UTIs) are the most common bacterial infection seen in women presenting to UK primary care, accounting for up to 3% of all GP consultations. Approximately 40-50% of women experience at least one episode during their lives. D-mannose, which is a sugar, is currently available as a food supplement. Some women find it very helpful in reducing the number of UTIs they experience, but others don’t. Previous research suggests that using D-mannose can reduce the number of UTIs experienced by women who have frequent UTIs. We aim to recruit 508 women to take the supplement or a placebo for six months. Our results should then give us the confidence to advise women who suffer with recurrent UTIs whether D-mannose might be helpful to manage their condition. 


Results published online in JAMA Internal Medicine on 08Apr2024.


Link to online publication:

Study Design: Phase IV, Two arm, individually randomised, double blind placebo controlled trial
Sponsor: University of Oxford
Ethical Approval:  REC No: 18/SW/0245
Chief Investigator: Dr Gail Hayward
Contact Details: