The Health Benefits of D-Mannose (2024)

D-mannose is sometimes used as a dietary supplement to treat or prevent urinary tract infections (UTIs). While it can’t replace medical treatment, some studies suggest it could be helpful when used alongside standard treatment.

This article discusses the benefits of D-mannose, whether it can help prevent UTIs, possible side effects, safety, 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.

What Is D-Mannose?

D-mannose in its natural form 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 supplement, D-mannose comes in the form of capsules and powders. D-mannose powder is mixed with water or unsweetened juice and taken as a liquid.

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.

How D-Mannose Is Used for UTIs

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 UTIs. Frequent UTIs are usually treated with a low-dose antibiotic taken for six months or longer.

The Health Benefits of D-Mannose (1)

UTI Prevention

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.

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, people in the supplement group and the antibiotic group had a significantly lower risk of recurrent UTIs compared to 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, larger, high-quality studies are needed to confirm these findings.

UTI Treatment

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. 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.

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 pilot 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.

The Health Benefits of D-Mannose (2)

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 for Using D-Mannose

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.

How Much D-Mannose Should I Take for UTIs?

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 taken daily or 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 daily in various supplement forms.

Consult your healthcare provider before taking D-mannose to confirm how much you should take.

When to Talk With a Healthcare Provider

If you experience recurrent UTIs, make an appointment with your healthcare provider to determine your best plan of action.

As with any new supplement, if you're thinking about trying a D-mannose supplement, talk with your healthcare provider first. They can help identify any risks or benefits specific to your health conditions.


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.

  1. 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

  2. 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

  3. Altarac 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

  4. 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

  5. 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

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

The Health Benefits of D-Mannose (3)

By Jennifer Lefton, MS, RD/N, CNSC, FAND
Lefton is a registered dietitian/nutritionist and certified nutrition support clinician with over 20 years of experience in clinical nutrition.

Originally written byCathy Wong

See Our Editorial Process

Meet Our Medical Expert Board

Was this page helpful?

Thanks for your feedback!

What is your feedback?

The Health Benefits of D-Mannose (2024)


Top Articles
Latest Posts
Article information

Author: Twana Towne Ret

Last Updated:

Views: 6387

Rating: 4.3 / 5 (44 voted)

Reviews: 83% of readers found this page helpful

Author information

Name: Twana Towne Ret

Birthday: 1994-03-19

Address: Apt. 990 97439 Corwin Motorway, Port Eliseoburgh, NM 99144-2618

Phone: +5958753152963

Job: National Specialist

Hobby: Kayaking, Photography, Skydiving, Embroidery, Leather crafting, Orienteering, Cooking

Introduction: My name is Twana Towne Ret, I am a famous, talented, joyous, perfect, powerful, inquisitive, lovely person who loves writing and wants to share my knowledge and understanding with you.