Bladder and prostate

Limited evidence

• Cranberry

  The fruit of an evergreen shrub from North America, sold as juice, tablets or capsules.

  • NHS: Some evidence on daily use when bladder infections keep coming back.
  • NICE: Evidence on repeat UTIs is uncertain, and there is none for older women.

  Also covered by NHS inform, NICE, BAUS and NCCIH.

• D-mannose

  A kind of sugar, sold over the counter as a powder or tablets.

  • NICE: Evidence came from a single study, of 200ml of 1% solution each evening.
  • BAUS: Only small studies so far on repeat urine infections; more evidence is needed.

  Also covered by NHS and NICE.

• Pumpkin seed oil

  Oil pressed from pumpkin seeds, sold in capsules.

  • Cleveland Clinic: Not enough evidence to know if it is safe or of any use.

No good evidence

• Saw palmetto

  The berries of a small palm tree native to the West Indies and the south-east coast of North America.

  • NCCIH: Little or no difference to enlarged-prostate symptoms in a 2023 review of 27 studies.

  Also covered by Cleveland Clinic, Harvard Health Publishing and NICE.

Advised against

• Zinc

  A mineral found in meat, shellfish, dairy foods such as cheese, bread and cereal products.

  • Cleveland Clinic: Research is mixed; long-term high-dose zinc could raise prostate cancer risk.
  • Harvard Health Publishing: Studies show no consistent effect on prostate health; 100mg a day might raise cancer risk.

Things to check

• NHS: Get problems peeing checked by a GP: they can sometimes be caused by more serious conditions, such as prostate cancer.
• NHS: With UTI symptoms, get an urgent GP appointment or call 111 if you are a man, pregnant, aged 65 or over or have diabetes.
• NCCIH: Do not use cranberry products in place of proven UTI treatment; see a clinician about a suspected UTI.
• NHS: If you take warfarin, avoid cranberry products.
• NHS: Speak to a doctor before taking D-mannose or cranberry products in pregnancy.
• NHS: D-mannose and cranberry products can contain a lot of sugar.
• NHS: Do not take more than 25mg of zinc supplements a day unless a doctor advises it.
• Cleveland Clinic: You cannot be sure of a prostate supplement's ingredients, strength or purity.

If you take medication, are pregnant, or have a health condition, check with a pharmacist or GP first.