D-Mannose For UTIs: Frequency, Dosage, And Much More

Written by: Jessica Guht
Jessica Guht
Categorized as UTI
Jessica Guht
Categorized as UTI

Many people experience urinary tract infections or UTIs throughout their lives. One possible method of treating, and in fact, preventing these infections is via the use of D-Mannose.

D-Mannose was first used back in the 1980s by Dr. Wright and is claimed to work wonders against UTIs, which are often caused by Escherichia coli (E. Coli). While anecdotal evidence is growing for the efficiency of this supplement, it is important to note that it is not FDA-approved or supported as a product to prevent or treat UTIs. 

However, with increasing clinical evidence coming out in support of D-Mannose for this purpose, it is hard to ignore the potential. Even in acute UTIs, D-Mannose has been proven to at least show promise, according to studies. There are very few side effects of taking D-Mannose, but these are completely manageable, so they should not be enough to put you off if you are experiencing a UTI.

To find out more about D-Mannose, keep reading! We will cover everything you need to know on the topic.

Table of Contents

What Exactly Is D-Mannose?

D-Mannose is a kind of sugar, but not the usual sugar that you are likely used to, which is glucose. While glucose can make your UTI symptoms worse, mannose can do a lot to improve them. 

Unlike other kinds of sugars, our bodies are not able to metabolize D-Mannose. This means that it quickly gets expelled from the blood and stored in urine instead. Because of this high concentration of it in your urine, D-Mannose can help to fight off the E. Coli bacteria that grow in your bladder, and therefore get rid of (and prevent) UTIs. 

Why Your Doctor Might Not Mention D-Mannose?

As we mentioned, D-Mannose is not FDA-approved for the use of treating or preventing UTIs. Since physicians are required to follow the official treatment guidelines that are outlined by the FDA, they may not necessarily be able to explain this as an option for you. If they do not follow the guidelines, they put themselves at risk of negligence and litigation issues. 

Not only that, but D-Mannose is a natural substance. This can mean that it is not well-regulated, so there may be extreme differences in quality between different supplements. As a result, you can never really know how well it is going to work. 

Finally, it’s worth mentioning that there are no large clinical trials that have been conducted to evaluate the effectiveness of D-Mannose. This is likely because there would be significant financial investments required, and no pharmaceutical company would be able to make any money from it. Since D-Mannose is a naturally occurring substance, it can’t be patented, and therefore will never be financially beneficial for anyone to even try to research it. 

With that being said, it’s interesting to point out that many physicians will recommend that individuals with UTIs should drink cranberry juice. Cranberry juice, which cannot be patented either, and has not equivocally been proven to be helpful in treating UTIs, is a popular choice, but few even know about D-Mannose. 

Prevention Is Always Better Than Cure

Before we jump into what you need to know about D-Mannose, it’s crucial to point out that prevention is always better than cure. Yes, D-Mannose can help to treat UTIs, but it can also help to prevent them. Even then, it is only one piece of the puzzle, and you need a holistic approach to prevent yourself from experiencing UTIs.

A holistic approach may help you not get UTIs, and therefore avoid being prescribed antibiotics. Of course, if you need them, then you should not try to make yourself think otherwise. Our healthcare professionals are there for a reason, and you should always heed what they say. 

Nonetheless, for a more holistic approach to preventing UTIs, consider the following:

  • Reduce your body’s pathogenic bacteria (D-Mannose comes in here)
  • Decrease bladder inflammation
  • Live a healthy lifestyle
  • Dissolve bacterial biofilms

Everything You Need to Know About D-Mannose for UTIs

Below, we will go through everything you need to know about D-Mannose for UTIs, including where people go wrong, and the dosage you should be aiming for. 

The Key Points

Don’t have the time to read through everything, or just don’t want to? Here are the basics of what you need to know:

  • Do not drink too much water too soon after taking D-Mannose. Aim to only have about half a glass with your first dose. You don’t want to dilute the D-Mannose too quickly
  • Opt for powder over capsules. This will keep the D-Mannose pure without any of the additional ingredients within the capsules
  • Remember to have a holistic approach to preventing and treating UTIs
  • Start taking D-Mannose as soon as possible, before the UTI fully develops
  • Never self-treat your UTI with D-Mannose for more than three days
  • Although E. Coli is responsible for the vast majority of UTIs, not all are. If your UTI is caused by something other than E. Coli, D-Mannose will not be a helpful solution
  • There are options if you have a corn allergy (as most D-Mannose comes from corn) since it can be made from other sources (such as Pure Encapsulations)

D-Mannose Common Mistakes

Unfortunately, there are a number of mistakes that people often make when they are taking D-Mannose to treat their UTIs. We will go through some of the most common mistakes that you might make so that you can avoid them in the future if you choose to use D-Mannose. 

Let’s take a look at what you need to know below. 

Drinking Too Much Water Too Soon

D-Mannose is only effective when it is in your bladder in high concentrations. As such, drinking a lot of water after taking a dose will only dilute it, and make it far less effective. To keep the potency up, make sure that you wait at least 45 minutes before drinking a lot. This will ensure that it does its thing. 

Here’s what you need to know:

  1. When taking your dose (one teaspoon), do so with no more than half a glass of water. 
  2. Wait at least 45 minutes before drinking more (an hour or more is preferable)
  3. After that, you can drink plenty of water so that you can flush your bladder and get rid of the harmful bacteria causing the issues. 

Doing it this way allows the D-Mannose to remain concentrated, and bind to the E. Coli bacteria. In turn, both the D-Mannose and bacteria will get flushed out. 

Choosing Capsules Over Powder

Capsules might seem like the easy option when you are choosing between them and powder, but they are not worth it. Not only are capsules more expensive, but they also contain a number of unnecessary ingredients. 

Popular added ingredients in capsules include things like silica, stearic acid, rice flour, and magnesium stearate. The only purpose of these ingredients is to process the powder into the capsules – avoid them and get more for your money. 

The best thing you can do is simply get pure D-Mannose powder, and measure out a teaspoon. Since this supplement is naturally sweet (seeing as it is a kind of sugar), it isn’t difficult to palate at all. You can even dissolve it in half a glass of water (no more than that).

Overall, while there are brands and products that will hand over your D-Mannose in a neat, measured-out capsule, they are not worth the extra money. It hardly takes any time at all to measure out a teaspoon and dissolve it in some water.

Do Not Only Rely on D-Mannose

It might be appealing to only stick to natural supplements to fight off and prevent UTIs, but they do not always work. This is especially the case for chronic UTIs. You need to use a holistic approach to cover all your bases, to get the best, reliable results. 

There are a number of natural and herbal remedies out there, but don’t let them keep you away from a doctor. If you need help, seek help. 

If you are experiencing your first UTI, take steps to prevent it from happening again. It may be a warning sign that something isn’t quite right – whether it is hormones, vaginal flora, stones, or something else. Be proactive.

Starting to Take D-Mannose Too late

Anecdotal evidence suggests that D-Mannose works best when it is taken as a preventative, or at the very least, as the first signs of a UTI. This allows the supplement to stay on top of the bacteria and not get overrun like it might in the case of a full-blown UTI. 

Even so, taking this supplement will be beneficial if you are experiencing a full-blown UTI. In these cases, you might still need a round of antibiotics to deal with the infection. 

It is crucial to note that if you do go on a course of antibiotics, you need to complete your course. Do not switch over to D-Mannose and stop the antibiotics halfway through, or else you are undoing all the hard work. You may develop drug-resistant bacteria if you do this.

You can still take D-Mannose alongside the antibiotics, but you should tell your doctor if you are. There is always a possibility that the D-Mannose will interact with the medication in some way, so it’s best to cover all your bases to be safe.

Some Things to Remember

There are some important things to remember when taking D-Mannose. We will go through two crucial things in the sections below. 

D-Mannose Is Not a Cure-All

D-Mannose is not a cure-all by any means. It isn’t magical, and there are no metaphysical properties to it. There are some health risks to be aware of if you choose to use D-Mannose to treat your UTI. These risks do not come from the D-Mannose itself, but rather the risk of the UTI not getting treated and the bacteria ascending to your kidneys. If this happens, it can cause a very serious infection. 

As such, you need to make a note of your symptoms. You should not only be relying on an OTC UTI test, as these can be wrong, too. Don’t hesitate to go to a healthcare professional if your symptoms last more than 2 days, or have not improved at all. 

D-Mannose only treats UTIs that are caused by E. Coli. Anyone who is more at risk of getting UTIs is more at risk of the UTI being caused by different bacteria. When this happens, the supplement will not help, so you may need to get medical help to prevent further health concerns, like kidney or blood infections.

Be Wary of Allergies

Most D-Mannose supplements come from corn, but there are other options if you have an allergy. Using a corn D-Mannose when you are allergic will only make symptoms worse and exacerbate your already unpleasant side effects, such as GI upset or hives. 

There are pineapple or cranberry options, or even supplements made from birch tree juice and various other berries. Ensure you do not put too much strain on your immune system, so take it easy and make sure you are not making it work harder than it needs to.

Acute UTI D-Mannose Dosage

If you are experiencing acute UTI, the typical dosage would be one full teaspoon of powder dissolved in half a glass of water every 2–3 hours or 1,500–2,000 mg in capsule form. After 2–3 days, you would switch over to a preventative dose for a further 2–3 days. 

Here are some things to remember when taking D-Mannose:

  • Remember to drink lots of water in between doses to properly flush out your system
  • Know that everyone might respond differently to the doses (overall health, weight, age, etc.)
  • The purity and quality of the D-Mannose will likely vary from one manufacturer to another
  • There are some possible side effects (nausea and diarrhea if taken for extended periods of time)
  • Let your doctor know you are taking D-Mannose so that they can determine if it will interact with antibiotics
  • Symptoms should diminish within 48 hours, but make sure you continue taking it for a further five days. If your symptoms do not alleviate, or they get worse, go to a healthcare professional.
  • You might want to take a dose a day for a month after the infection has cleared up, just to prevent any further episodes

Remember – not all D-Mannose uses form, so there are ways to get around it if you have allergies!

UTI Prevention D-Mannose Dosage

There may be some trigger events that can cause a UTI. If you know what these are, you can take D-Mannose after these events to prevent a UTI from forming.

Here’s what you can do for a prevention dose:

  • Take 1,500–2,000 mg (or half a teaspoon) either once or twice a day
  • It is safe to take this for as long as you need, since the bacteria will not become resistant to it. 
  • Feel free to take D-Mannose anytime you think your vaginal flora might be compromised (e.g., after eating lots of sugar, signs of a yeast infection, after sex, being very stressed, etc.)

Where Can You Get D-Mannose Products?

As with many things, the more you buy of something, the cheaper it tends to be. Opt for large batches with large volumes, and you can keep the cost down. Check out places like Amazon for these supplements for some of the best prices out there. 

You can probably find it in a variety of stores, too, but prices will be much higher than expected.   

How Can DrHouse Help You?

DrHouse is a telehealth platform that allows you to make on-demand visits with online doctors.

At DrHouse, we understand that UTIs can be difficult and sometimes embarrassing. With us, you can get discreet and personalized advice to help you identify the cause of your infection, treatment plans, and prevention tips. So don’t hesitate to reach out if you need help. We are here for you.


Is D-Mannose Suitable for Children?

Yes, it is safe! However, the dosage will need to be altered depending on weight and age. There may also be rare cases of genetic diseases that may impact the efficiency of D-Mannose. 

Ultimately, you should still speak to a doctor, especially if the child is young. 

Can Diabetics Use D-Mannose?

This might be different for everyone. You should definitely speak to your doctor if you have diabetes and wish to take D-Mannose. While we think it is safe, as only time amounts of the sugar are metabolized in the body, it’s always better to ask for the opinion of a professional. 

How Quickly Does D-Mannose Prove Relief for UTIs?

If your UTI has been caused by E. Coli, you should notice a reduction in your symptoms within 24–48 hours. If this doesn’t happen, you should go to your doctor, as an untreated UTI can develop into various more serious conditions like kidney or blood infections. 

Key Takeaways

D-Mannose, while not FDA-approved, shows very promising signs of being an excellent way to treat and prevent UTIs. The supplement is easy to use, and you typically need to have one teaspoon every three or so hours for 2–3 days. 

However, this supplement does not treat all UTIs – only the ones caused by E. Coli bacteria. So, if you do not see an improvement in your symptoms after 2–3 days, or they get worse, make sure to speak to a healthcare professional. These supplements are not meant to replace doctor visits!


  • Roy R, Tiwari M, Donelli G, Tiwari V. Strategies for combating bacterial biofilms: A focus on anti-biofilm agents and their mechanisms of action. Virulence. 2018 Jan 1;9(1):522-554. doi: 10.1080/21505594.2017.1313372. PMID: 28362216; PMCID: PMC5955472
  • Domenici L, Monti M, Bracchi C, Giorgini M, Colagiovanni V, Muzii L, Benedetti Panici P. D-mannose: a promising support for acute urinary tract infections in women. A pilot study. Eur Rev Med Pharmacol Sci. 2016 Jul;20(13):2920-5. PMID: 27424995.
  • Kranjčec B, Papeš D, Altarac S. D-mannose powder for prophylaxis of recurrent urinary tract infections in women: a randomized clinical trial. World J Urol. 2014 Feb;32(1):79-84. doi: 10.1007/s00345-013-1091-6. Epub 2013 Apr 30. PMID: 23633128.
  • Porru, D., Parmigiani, A., Tinelli, C., Barletta, D., Choussos, D., Di Franco, C., Bobbi, V., Bassi, S., Miller, O., Gardella, B., Nappi, R., Spinillo, A., & Rovereto, B. (2014). Oral D-mannose in recurrent urinary tract infections in women: A pilot study. Journal of Clinical Urology. https://doi.org/10.1177/2051415813518332 
  • What causes UTIs & UI? Eunice Kennedy Shriver National Institute of Child Health and Human Development. Available from: https://www.nichd.nih.gov/health/topics/urinary/conditioninfo/causes

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