Bladder Health

How much D-Mannose should you take for UTI?

By Dave Smith

Feb 23, 2022

how much d-mannose to take

How much D-Mannose should you take for UTI?

The information in this article pertains to Waterfall D-Mannose . Not all D-Mannose is created equal. Waterfall D-Mannose is 100% pure D-Mannose, undiluted by additives such as cranberry extract, inactive substances (fillers) or other excipients which may have adverse biological effects.

D-Mannose Dosage

The effectiveness of D-Mannose when used to combat an E. coli infection varies from person to person depending on weight, severity of infection and other biological factors such as gut health, ability to absorb the D-Mannose through the small intestine and pre-existing conditions such as Crohn's disease or SIBO. D-Mannose tablets can be taken with water or your favorite beverage, the powder can also be mixed into your favorite beverage. Avoid urine acidifying beverages such as cranberry juice and alcohol.

When Symptomatic

For rapid relief, ingest three grams of pure D-Mannose with a glass of water every 3 hours, day and night for the first 48 hours. Do not skip the night doses, set your alarm. Gradually reduce frequency over the next few days as symptoms improve. Reduce to prophylactic dose, 2 grams daily, once symptoms have completely subsided.

You may experience 2-3 more flare ups before all embedded bacteria have been removed and your propensity for attacks diminishes. If the infection has reached the kidneys (you may feel lower back pain, sick or have a fever), see your Doctor immediately.

Prophylactic Dose

To help prevent recurrence, ingest two grams of pure D-Mannose with a glass of water once a day. This Randomized Clinical Trial has demonstrated a 2 gram daily dose of pure D-Mannose prevented recurrence of acute cystitis in 85.4% of women with a history of recurrent UTI, perfoming 4 times better than the prescribed antibiotic.


  • Take 3 grams of Waterfall D-Mannose one hour before intimacy. Refrain from urinating.
  • Urinate immediately afterwards, then take another 3 grams.
  • For the next 48 hours take 3 grams every 4 - 6 hours.
  • Maintain normal hygiene standards.
  • Maintain this protocol around intimacy for a few months.
  • Gradually, you should begin to see improvement.

Waterfall D-Mannose is as effective for men as it is for women. Men with a propensity for cystitis may find it beneficial to urinate after being intimate.

Cystitis problems in men may be an indication of a more serious problem such as a prostate condition, and should be thoroughly investigated by a Doctor. For more information, please see our page on Male Urinary Problems.

For best results, or stubborn infections

Anecdotal evidence and customer feedback suggests the following practices substantially increase effectiveness:

  • An hour after ingesting D-Mannose with a glass of water, if possible, drink another glass or two of water. This will help flush the E. coli bacteria, which has attached to the D-Mannose, from your system and clear the urinary tract of bacteria.
  • Continue to use prophylactically even after symptoms has subsided. Bacteria embed themselves deep in the bladder wall when escaping attack from D-Mannose and may lay dormant behind biofilms until conditions are favourable.
  • Remember, D-Mannose is simply a sugar which is not metabolized. It passes through your urinary system, attaching to bacteria, and is then expelled through urine. This makes it safe to use with children as well as diabetics.
  • Keep the urine's pH at or slightly below 7 during the course of your D-Mannose regimen. Bacteria thrive in an acidic environment doubling in numbers every 20 - 40 minutes. Conversely, bacterial growth is inhibited in a more alkaline environment.

Pregnant Women, Children, Babies, and Pets

Unlike medications such as antibiotics which are classed as chemical substances, D-Mannose is a completely natural simple sugar, classed as a supplement.

D-Mannose will cross the placental barrier, but is most unlikely to cause any damage to the foetus, just as a spoonful of regular table sugar would not. Research shows that the unborn baby requires D-Mannose, which is naturally produced by the human body, for normal development. If you are pregnant we strongly recommend that you consult a medical professional before taking the D-Mannose or any other supplement.

For children, babies, and pets, the dose should be adjusted according to proportion of adult human weight, and the amount of fluids they drink.


The dose of D-Mannose for catheterised people, men or women, generally needs to be higher than the dose for people who do not catheterise. The actual amount you need to take is best found best by trial and error. Begin with the recommended adult or child dose, and gradually increase daily if necessary.

Urethral Infections

Urethral infections may take longer to subside because D-Mannose rapidly passes through the urethra when you urinate, rather than lingering as it does in the bladder. To increase effectiveness, you might want to try a method recommended by Doctors when a mid-stream urine sample is required: when your bladder is almost empty and there's little pressure remaining behind the flow, with a clean palm, press up against the urethra using just enough pressure to moderate the flow, until your bladder is completely emptied. You can repeat this each time you urinate with D-Mannose in your system.

This method provides the D-Mannose with a little extra time to detach the bacteria from your urethral wall. It can take anywhere from one to seven days to clear urethral symptoms. Contracting your muscles, sometimes referred to as 'bladder control', is not as effective as the palm pressure method as your urethra would not be full of urine.

Remember cystitis-like symptoms may be caused by other problems such as blockages, bladder stones, prostate problems, failing kidneys, STDs and viral or fungal infections. Please see your Doctor if symptoms persist.

Other Considerations

Research has shown that bacteria can thrive in a very acidic environment. Avoiding acidifying foods and drinks, primarily orange and cranberry can have significant benefits. Changing to a diet that makes your urine more alkaline is highly recommended.

Patients with Enteritis, Celiac disease, Crohn's disease, or Whipple's disease, parasitic infections (such as Giardiasis or Hookworm) or who generally have problems absorbing nutrients from food, may have problems absorbing D-Mannose. Very high levels of intestinal bacteria (especially E. coli or Salmonella) may also reduce the amount of pure, unadulterated D-Mannose that reaches the urinary system. The solution in these cases is to either increase the dose, increase the frequency, or increase both the dose and frequency.

On the other hand, people with Hodgkin's disease, or Scleroderma or similar, may have enhanced nutrient absorption ability and may require less D-Mannose to achieve the same effect.

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