Indications
D-mannose is a natural sugar, related to glucose, found in small amounts in fruits such as cranberries, apples and oranges. It is used as a supplement to help prevent repeated urinary tract infections (UTIs), especially bladder infections (cystitis) in women. It is often combined with cranberry extract. Some studies suggest it may reduce how often infections come back, but it is not a proven treatment for an active infection and does not replace antibiotics when they are needed.
How It Works
Most UTIs are caused by E. coli bacteria, which stick to the bladder wall using tiny hair-like structures. D-mannose is absorbed and then passed out in the urine, where the bacteria attach to it instead of to the bladder wall. The bacteria are then washed out when you pass urine. Very little D-mannose is used by the body for energy, so it has little effect on blood sugar at usual doses.
Dosage and Administration
Take as directed on the label or by your doctor, usually once or twice a day. Powders are dissolved in a glass of water; tablets or capsules are swallowed with water. Drink plenty of fluids during the day and empty the bladder regularly.
Interactions
- No important drug interactions are well known.
- People with diabetes taking medicines such as Metformin or Insulin should check their blood sugar when starting it, especially at higher doses.
- It can be used alongside antibiotics prescribed by a doctor, but does not replace them.
Contraindications
- Allergy to D-mannose or any ingredient (for example cranberry, if included).
- Rare inherited problems with sugar metabolism, unless a doctor advises it.
Side Effects
It is usually well tolerated. Bloating, wind and loose stools may occur, especially with high doses.
Get urgent medical help if UTI symptoms come with fever, chills, pain in the back or side, vomiting or blood in the urine, as these may mean a kidney infection. Also seek help for signs of an allergic reaction such as swelling of the face or difficulty breathing.
Pregnancy and Lactation
There is not enough information on its safety in pregnancy and breastfeeding. UTIs in pregnancy need prompt medical treatment; use D-mannose only if your doctor advises it.
Precautions and Warnings
- See a doctor if you have UTI symptoms (burning, frequent urination, cloudy or smelly urine) that do not improve within 1 to 2 days, or if you are a man, pregnant, or a child with these symptoms.
- People with diabetes should monitor blood sugar.
- People with kidney disease should ask their doctor first.
Overdose
Large amounts may cause diarrhoea, bloating and stomach upset. Rarely, kidney problems have been suggested with very high long-term doses. Seek medical advice if a large amount is taken.
Therapeutic Class
Urinary tract health supplement (monosaccharide).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children. Keep the container tightly closed.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.