D-mannose is a type of sugar found in certain fruits and vegetables, including cranberries,cabbage, and tomatoes. It's also produced in the body from glucose, another form of sugar. D-mannose is also called mannose.
As a dietary supplement, D-mannose is sometimes used to prevent urinary tract infections (UTIs) or bladder inflammation (cystitis) from infections. Though more research is needed, some studies suggest it could be helpful when used alongside standard treatment.
This article describes the purported uses of D-mannose, possible side effects, and what to look for in a supplement.
Dietary supplements are not regulated like drugs in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. Choose a supplement tested by a trusted third party, such as USP, ConsumerLabs, or NSF, when possible.
However, even if supplements are third-party tested, that doesn’t mean they are safe for all or effective in general. Therefore, it is important to talk to your healthcare provider about any supplements you plan to take and check in about potential interactions with other supplements or medications.
Supplement Facts
- Active ingredient(s): D-Mannose
- Alternate name(s): Mannose
- Legal status:Recognized as a dietary supplement by the FDA, not intended to prevent or treat UTI
- Suggested dose: D-mannose dosages ranging from 420 milligrams (mg) daily to 3 grams (g) have been used in studies. Follow the instructions on the supplement label and consult your healthcare provider.
- Safety considerations: It can cause mild side effects; people with certain health conditions should use caution; not enough is known about its safety to support use during pregnancy, breastfeeding, or in children.
Purported Uses of D-Mannose
There is some evidence that D-mannose may prevent or treat UTIs. A number of small studies have suggested that D-mannose may help keep E. coli —the bacteria responsible forthe vast majority of these infections—from sticking to the cells lining the urinary tract. More research is needed to confirm these effects. It should not be used to replace traditional treatment.
More than 7 million healthcare provider visits a year are due to this type of infection. Frequent UTIs are usually treated with a low-dose antibiotic taken for six months or longer.
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UTI Prevention
Several studies have looked at the use of D-mannose to prevent returning UTIs:
- A study published in the World Journal of Urology examined the use of D-mannose compared with the antibiotic nitrofurantoin or no treatment for six months in 308 women with a history of recurrent UTIs. After one week of initial treatment, both people in the supplement group and the antibiotic group had a significantly lower risk of recurrent UTIs than the no-treatment group. Still, it did not prevent recurrent UTIs in all women in the study. The people in this study used a powder formulation of D-mannose.
- One systematic review of seven studies could not determine if taking D-mannose long-term compared with no treatment, other supplements, or antibiotics reduced the number of repeated UTIs.
- Another systematic review of eight studies showed that D-mannose appears to have a protective effect against recurrent UTIs compared with placebo. The review also suggested that D-mannose may be similarly effective to antibiotics for prevention. However, the researchers cautioned that not enough studies are available to confirm this, and existing studies are small in size and vary in study design and quality.
When used as a supplement, D-mannose may help prevent recurrent UTIs. However, more extensive, high-quality studies are needed.
UTI Treatment
It's important to remember that supplements should not replace traditional medical treatment. If you think you have a UTI, seek medical advice from a healthcare provider.
Studies have looked at whether D-mannose can help treat active UTIs. While some research has suggested the supplement may help when used in addition to antibiotics, remember that these studies are often small and low in quality.
The following studies examined the use of D-mannose for treating UTIs:
- A small study of 43 women found that D-mannose taken twice daily for three days during an infection followed by once a day for 10 days resulted in a significant improvement in symptoms, UTI resolution, and quality of life. Those who received D-mannose for six months following treatment had a lower recurrence rate than those who took nothing.
- A systematic review of seven studies suggested that D-mannose may help improve UTI symptoms in the short term. However, the researchers noted that the findings were based on a limited number of small studies and should be considered cautiously.
- A review published in 2015 concluded that there is a lack of strong evidence that D-mannose—and other remedies like cranberry juice and vitamin C—should be used as a replacement for antibiotics in treating UTIs.
Research is ongoing and more studies are needed.
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UTI Claims About Cranberries
What Are the Side Effects of D-Mannose?
Common side effects of D-mannose reported in studies include:
- Bloating
- Loose stools
- Diarrhea
Precautions
Since D-mannose exits the body in urine, there is some concern that high doses may injure or impair the kidneys.
D-mannose can also potentially affect blood glucose levels in people with diabetes.
Not enough is known about the safety of the supplement during pregnancy or breastfeeding, so it should be avoided. Children shouldn't take D-mannose, either.
You should not self-treat a UTI with D-mannose or otherwise avoid or delay standard care, as doing so can lead to serious complications, including a kidney infection and even permanent kidney damage.
Dosage: How Much D-mannose Should I Take?
While D-mannoseis typically considered safebecause it occurs naturally in many foods, doses higher than consumed through a normal diet may be toxic or otherwise harmful. In addition, little is known about the long-term safety of D-mannose at any dose.
There are currently no standard guidelines for D-mannose dosages. In studies, D-mannose dosages have ranged from as little as 420 milligrams per day to 3 grams in various supplement forms.
Consult your healthcare provider before taking D-mannose to confirm how much you should take.
Frequently Asked Questions
Will taking D-mannose prevent or treat UTIs?
Some research has suggested that D-mannose supplementation helps prevent recurrent UTIs when compared with a placebo. It may also be similarly effective to antibiotics for preventive use. However, larger, higher-quality studies are needed to confirm these findings.
There is less evidence to suggest that D-mannose will treat an active UTI. However, studies have shown that, when used in addition to antibiotics, it may help improve symptoms. Therefore, never use D-mannose as a replacement for standard treatment.
Although it may help, D-mannose isn't guaranteed to prevent UTIs from returning. If you experience recurrent UTIs, make an appointment with your healthcare provider to determine your best plan of action. Always consult a healthcare provider before starting any new supplement.
What sources of D-mannose are available?
D-mannose can be consumed through food such as cranberries, green beans, and tomatoes. It is also available in oral supplement form as capsules or a powder mixed in with water or unsweetened juice.
What are the side effects of taking D-mannose?
(Video) D Mannose Health Benefits and TreatmentD-mannose is considered relatively safe and well-tolerated. Side effects such as diarrhea and bloating can happen. It can also potentially harm the kidneys if taken in high doses.
Talk to your healthcare provider before starting D-mannose to ensure it is safe for you, especially if you have any health conditions.
Sources of D-mannose & What to Look For
D-mannose occurs naturally in:
- Cranberries
- Black and red currants
- Peaches
- Green beans
- Cabbage
- Tomatoes
D-mannose supplements are available in capsule or powder form. D-mannose powder is mixed with water or unsweetened juice and taken as a liquid.
It's important to remember that dietary supplements haven't been tested for safety and are largely unregulated in the United States.
Whenshopping for supplements, look for products certified by ConsumerLab, The U.S.Pharmacopeial Convention, or NSF International. These organizations don't guarantee a product is safe or effective, but their seal indicates that a supplement has undergone testing for quality.
Summary
Preliminary studies suggest that D-mannose holds promise as a way to help prevent UTIs. However, larger, high-quality studies are needed to confirm the findings and the safety of D-mannose supplements.
If you're still thinking of trying D-mannose to prevent UTIs, talk with your healthcare provider first to weigh the pros and cons and decide whether it's a good option for you.
12 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Porru D, Parmigiani A, Tinelli C, et al. Oral D-mannose in recurrent urinary tract infections in women: a pilot study.Journal of Clinical Urology. 2014;7(3):208-213. doi:10.1177/2051415813518332
Lenger SM, Bradley MS, Thomas DA, Bertolet MH, Lowder JL, Sutcliffe S. D-mannose vs other agents for recurrent urinary tract infection prevention in adult women: a systematic review and meta-analysis. Am J Obstet Gynecol. 2020;223(2):265.e1-265.e13. doi:10.1016/j.ajog.2020.05.048
(Video) D-Mannose & How I Cured My Chronic UTIs Without Antibiotics | D Mannose For UTI PreventionAltarac S, Papeš D. Use of D-mannose in prophylaxis of recurrent urinary tract infections (UTIs) in women: Comment.BJU Int. 2014;113(1):9-10. doi:10.1111/bju.12492
Scribano D, Sarshar M, Prezioso C, et al. D-mannose treatment neither affects uropathogenic escherichia coli properties nor induces stable FimH modifications.Molecules. 2020;25(2):316. doi:10.3390/molecules25020316
Medina M, Castillo-Pino E. An introduction to the epidemiology and burden of urinary tract infections.Therapeutic Advances in Urology. 2019;11:175628721983217. doi:10.1177/1756287219832172
Ahmed H, Davies F, Francis N, Farewell D, Butler C, Paranjothy S. Long-term antibiotics for prevention of recurrent urinary tract infection in older adults: systematic review and meta-analysis of randomised trials. BMJ Open.2017;7(5):e015233.doi:10.1136/bmjopen-2016-015233
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;32(1):79-84. doi:10.1007/s00345-013-1091-6
Cooper TE, Teng C, Howell M, Teixeira-Pinto A, Jaure A, Wong G. D-mannose for preventing and treating urinary tract infections. Cochrane Database Syst Rev. 2022;8(8):CD013608. doi:10.1002/14651858.CD013608.pub2
Domenici L, Monti M, Bracchi C, et al. D-mannose: a promising support for acute urinary tract infections in women. A pilot study. Eur Rev Med Pharmacol Sci. 2016;20(13):2920-2925.
Parazzini F, Ricci E, Fedele F, Chiaffarino F, Esposito G, Cipriani S. Systematic review of the effect of D-mannose with or without other drugs in the treatment of symptoms of urinary tract infections/cystitis (Review). Biomed Rep. 2022;17(2):69. doi:10.3892/br.2022.1552
Aydin A, Ahmed K, Zaman I, Khan MS, Dasgupta P. Recurrent urinary tract infections in women. Int Urogynecol J. 2015;26(6):795-804. doi:10.1007/s00192-014-2569-5
Ala-Jaakkola R, Laitila A, Ouwehand AC, Lehtoranta L. Role of D-mannose in urinary tract infections - a narrative review. Nutr J. 2022;21(1):18. doi:10.1186/s12937-022-00769-x
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By Jennifer Lefton, MS, RD/N, CNSC, FAND
Jennifer Lefton, MS, RD/N-AP, CNSC, FAND is a Registered Dietitian/Nutritionist and writer with over 20 years of experience in clinical nutrition. Her experience ranges from counseling cardiac rehabilitation clients to managing the nutrition needs of complex surgical patients.
Originally written byCathy Wong
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Cathy Wong
Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health.
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FAQs
Is D-mannose good to take daily? ›
D-mannose is best taken on an empty stomach. Take 1 or 2 capsules daily, to help prevent urinary tract infections. D-mannose is safe for long term use. If you have the symptoms of a urinary tract infection for more than 2 days please see your doctor.
What are the side effects of taking D-mannose? ›Side effects of taking D-mannose
Most people who take D-mannose don't experience side effects, but some might have loose stools or diarrhea. If you have diabetes, talk with your doctor before taking D-mannose. It makes sense to be cautious since D-mannose is a form of sugar.
“In its concentrated form, it may help bacteria from sticking to the bladder wall and urinary tract lining which can then in turn, reduce infection rate' says Grace Barnes, Glamour's resident nutritionist. “This means it is great not only for treating a UTI but also to prevent it if there is a common recurrence.
Who should not use D-mannose? ›Doses higher than what is consumed through normal dietary intake, however, may result in abdominal bloating or diarrhea. D-mannose supplements should not be used during pregnancy or when breastfeeding, and individuals with diabetes mellitus should not take d-mannose.
Is D-mannose hard on kidneys? ›High doses of D-mannose may cause kidney damage. Always tell your doctor about any supplements you are taking, including natural ones and those bought without a prescription. That way, your doctor can check on any potential side effects or interactions with any medications.
Is D-mannose anti inflammatory? ›D-mannose exhibits strong anti-inflammatory properties, but whether it has beneficial effects on preventing and treating osteoporosis remains unknown.
What bacteria Does D-mannose work for? ›D-mannose may be effective as a treatment for an acute UTI caused by E. coli. D-mannose may effectively relieve acute UTI symptoms caused by type 1 fimbriae-positive bacteria.
How long does it take D-mannose to cure UTI? ›If you started taking D-Mannose at the first signs of a UTI, you typically would notice a drastic reduction in symptoms between 24 to 48 hours. However, if you don't notice an improvement, make sure to see your physician right away.
Is D-mannose like an antibiotic? ›The natural sugar d-mannose is considered as an alternative to antibiotics due to its ability to mask the bacterial adhesin FimH, thereby preventing its binding to urothelial cells.
How long should I take D-mannose for? ›When taken by mouth: D-mannose is possibly safe for most adults when taken for up to 6 months. It can cause diarrhea and nausea. There isn't enough reliable information to know if d-mannose is safe or what the side effects might be when taken for more than 6 months.
How many times a day should you take D-mannose? ›
Prophylactic Dose
To help prevent recurrence, ingest two grams of pure D-Mannose with a glass of water once a day.
Most of the studies also showed D-mannose can play a role in the prevention or rUTI or urodynamics-associated UTI and can overlap antibiotic treatments in some cases. The possibility to combine D-mannose with polyphenols or Lactobacillus seems another important option for UTI prophylaxis.
Can D-mannose cause diabetes? ›Risks for people with diabetes
D-mannose can combine with proteins in the body to form glycoproteins, which are present in cell membranes and other tissues. The way the body metabolizes glycoproteins can affect a person's risk of developing diabetes.
The following studies examined the use of D-mannose for treating UTIs: A small study of 43 women found that D-mannose taken twice daily for three days during an infection followed by once a day for 10 days resulted in a significant improvement in symptoms, UTI resolution, and quality of life.
What can I take daily to prevent UTI? ›- Urinary tract infections (UTIs) are a common problem. ...
- Probiotics are dietary supplements that contain live bacteria.
D-mannose alleviates osteoarthritis progression by suppressing HIF-2α-mediated chondrocyte sensitivity to ferroptosis, indicating D-mannose to be a potential therapeutic strategy for ferroptosis-related diseases.
What autoimmune disease is D-mannose? ›D-mannose is a C− 2 epimer of glucose that exhibits immunoregulatory effects in models of autoimmune diseases, such as type 1 diabetes, induced rheumatoid arthritis, and airway inflammation.
Does D-mannose irritate the bladder? ›Another side effect that some people report is that D-Mannose can irritate the bladder. Some users complain about symptoms similar to a urinary tract infection (UTI) when they use D-Mannose for prevention. The symptom seems to go away once you stop taking D-Mannose.
Is D-mannose a probiotic? ›SUPPLEMENT FACTS
Some studies suggest D-mannose may also play a useful role as a “prebiotic” by increasing the growth of good bacteria.
How much D-mannose do you take for a UTI? There is no standard dosage for D-mannose for UTIs. Studies on oral D-mannose to help prevent UTI have used amounts as varied as 420 milligrams to 2 grams a day, and some studies suggest taking D-mannose more than once a day.
Does D-mannose make you gain weight? ›
D-Mannose in your body
Your body does not metabolize D-Mannose like other sugars, and that's why D-Mannose powder does not affect the blood sugar levels, and therefore is safe for the diabetics and does not cause weight gain. D-Mannose does not kill the bacteria and therefore does not increase its resistance.
Drink cranberry juice. Large amounts of vitamin C limit the growth of some bacteria by acidifying the urine. Vitamin C supplements have the same effect.
Does D-mannose affect gut bacteria? ›Mannose increases the Bacteroidetes to Firmicutes ratio in the gut microbiota, a signature associated with the lean phenotype. These beneficial effects of mannose are observed when supplementation is started early in life.
Can I take D-mannose with probiotics? ›All three options – probiotics, cranberry juice, and D-mannose powder – can effectively fight off bacteria that cause UTI. You can take all three separately, but it's rather inconvenient, don't you think? What if you can just take a supplement that has all 3 ingredients in it? Fortunately, such a product exists!
What are the side effects of cranberry and D-mannose tablets? ›In some cases, you may experience vomiting, nausea, or diarrhea. Most of these side effects of CRANBERRY EXTRACT+D MANNOSE do not require medical attention and gradually resolve over time. However, if the side effects persist or worsen, please consult your doctor.
Which fruits contain D-mannose? ›A close cousin of D-glucose, the simple sugar D-mannose provides a natural approach to urinary tract health. Several different fruits and vegetables carry the simple sugar including cranberries, apples, pineapples, peaches, and broccoli.
Can you take azo and D-mannose together? ›Can I take AZO® D-Mannose alongside other products? We recommend you to speak with your healthcare professional about taking D-mannose with other products, however, there is no scientific reason to believe there is a concern with D-mannose and other products.
Does D-mannose help with yeast infections? ›Treatment Options for Yeast Infections
Widely recommended by OB/GYNs, these probiotics with added cranberry and D Mannose, encourage a healthy pH balance and help to prevent further yeast infections.
When taken by mouth: D-mannose is possibly safe for most adults when taken for up to 6 months. It can cause diarrhea and nausea. There isn't enough reliable information to know if d-mannose is safe or what the side effects might be when taken for more than 6 months.
How often should you take D-Mannose? ›D-Mannose Dosage For UTI Prevention
The UTI prevention dose is 1500-2000 mg (or one-half teaspoon) once or twice a day. You can take this “preventive” dose safely for as long as you want. The bacteria won't develop resistance to D-Mannose.
How long does D-mannose stay in bladder? ›
The known half‐life of D‐mannose is approximately 4 hours as it is known to be metabolised rapidly by the human digestive system (Hu 2016). Interactions with other treatments are currently uncertain.
Does D-mannose affect good bacteria? ›Our results indicate that high d-mannose concentrations have no effect on bacterial growth and do not interfere with the activity of different antibiotics. d-mannose ranked as the least preferred carbon source to support bacterial metabolism and growth, in comparison with d-glucose, d-fructose, and l-arabinose.
Do urologists recommend D-mannose? ›D-mannose use for the prevention of relapses of INMP is indicated in the clinical recommendations of the American (AUA) and European (EUA) urological associations.
Can D-mannose irritate the bladder? ›Another side effect that some people report is that D-Mannose can irritate the bladder. Some users complain about symptoms similar to a urinary tract infection (UTI) when they use D-Mannose for prevention. The symptom seems to go away once you stop taking D-Mannose.
What bacteria does D-mannose work for? ›D-mannose is commonly marketed as a dietary supplement for urinary tract health. Research suggests that free D-mannose in urine has the potential to saturate E. coli FimH structures, and subsequently block E. coli adhesion to urinary tract epithelial cells.
How often should I take D-mannose to prevent UTI? ›How much D-mannose do you take for a UTI? There is no standard dosage for D-mannose for UTIs. Studies on oral D-mannose to help prevent UTI have used amounts as varied as 420 milligrams to 2 grams a day, and some studies suggest taking D-mannose more than once a day.