Is D-mannose or cranberry better for preventing UTIs?
Cranberry has the stronger evidence. A 2023 Cochrane review of 50 studies found that cranberry products lowered the risk of UTIs, including in women with recurrent infections. In the largest placebo-controlled trial of D-mannose, published in 2024, 2 grams a day did no better than placebo. Neither one treats an infection you already have.
D-mannose vs cranberry, at a glance
| Question | D-mannose | Cranberry |
|---|---|---|
| What is it? | A sugar found in most diets | A fruit rich in compounds called PACs |
| Best evidence | 2024 trial, 598 women: no better than placebo | 2023 Cochrane review, 50 studies: lower UTI risk |
| Women with recurrent UTIs | 51.0% had a UTI vs 55.7% on placebo | About 26% lower risk |
| U.S. urology guideline | Alone, may not be effective | Should be offered as an option |
| Treats an active UTI? | No good evidence | Not recommended |
| Side effects reported | Few: diarrhea, vaginal burning | Stomach upset or diarrhea in very large amounts |
What is the difference between D-mannose and cranberry?
D-mannose is a sugar, and cranberry is a fruit, but both are sold for the same reason: the idea that they stop bacteria from sticking to the bladder wall. A 2022 Cochrane review describes D-mannose as a sugar found within most diets. In cranberry, the compounds thought to do this job are proanthocyanidins, or PACs.
That shared idea is why the two are compared so often, and why many supplements combine them. The mechanism sounds convincing. What matters, though, is whether women who take them actually get fewer infections, and that is where the two part ways.
I've dealt with recurrent UTIs myself, so I know how tempting it is to try anything on the shelf. My experience isn't evidence, though, which is why this guide sticks to what the trials found.
Does D-mannose work for UTI prevention?
Not in the best trial so far. A 2024 study in JAMA Internal Medicine followed 598 women with recurrent UTIs across 99 primary care centers in the UK. Half took 2 grams of D-mannose daily for six months, and half took a placebo. A suspected UTI needing care occurred in 51.0% and 55.7%, a difference that was not statistically significant.
The researchers also found no significant differences in symptom duration, antibiotic use or the number of infections. Their conclusion was direct: D-mannose should not be recommended for prevention in this group of women.
Earlier research was too thin to settle the question. A 2022 Cochrane review found only seven small trials with 719 participants, most with a high or unclear risk of bias, and concluded there was little to no evidence to support or refute D-mannose. It called for one large placebo-controlled trial, which is what the 2024 study delivered.
Does cranberry work for UTI prevention?
Yes, for some groups, according to the largest review available. A 2023 Cochrane review pooled 50 studies with 8,857 participants and found that cranberry products reduced the risk of UTIs by about 30%, with moderate-certainty evidence. In women with recurrent UTIs, the reduction was about 26%, based on 8 studies with 1,555 participants.
The National Center for Complementary and Integrative Health (NCCIH), part of the U.S. National Institutes of Health, gives a similar figure: cranberry products may decrease the overall risk of symptomatic, recurrent UTIs in women by 25 percent. It adds a caution, saying the effectiveness of cranberry is still in question because of inconsistent findings.
Cranberry did not help everyone in the Cochrane review. There was little or no benefit in elderly people living in care institutions, in pregnant women, or in adults with bladder-emptying problems caused by nerve conditions.
What do urology guidelines say about D-mannose and cranberry?
The American Urological Association (AUA) treats them differently. Its guideline on recurrent UTIs in women, amended in 2025, says clinicians should offer cranberry as an option for prevention. The same guideline says clinicians should inform patients that D-mannose alone may not be effective in UTI prevention. Both statements are moderate recommendations with Grade B evidence.
That is a clear signal from the specialists who treat these infections. Cranberry is on the list of reasonable options to discuss with your doctor. D-mannose on its own is not.
Should you take cranberry and D-mannose together?
There is no good evidence that the combination works better than cranberry alone. The 2022 Cochrane review found one small study of D-mannose combined with herbal supplements, with 40 participants and very uncertain results. The AUA guideline speaks only of D-mannose alone, and the 2024 trial tested D-mannose by itself, so the combination remains largely unstudied.
Many products pair the two ingredients, so this is a fair question to bring to your doctor or pharmacist. In a combined product, cranberry is the ingredient with supporting research.
Can you flush out a UTI with D-mannose or cranberry?
No. Neither one is a treatment for an infection you already have. The NCCIH states that cranberry is not recommended as a treatment for existing UTIs in any population, and warns against using cranberry products instead of a proven treatment. The 2022 Cochrane review found little to no evidence that D-mannose treats UTIs either.
Burning, urgency, fever or pain in your back or side are reasons to call your doctor, not to reach for a supplement. The AUA guideline recommends a urine test and culture with each symptomatic episode before treatment starts. A UTI can also be one reason for night-time bathroom trips, which we cover in why you pee so much at night.
Is there a downside to taking D-mannose or cranberry?
Reported side effects are mild, but the safety data are limited. In the 2022 Cochrane review, side effects of D-mannose were few and poorly reported, mostly diarrhea and vaginal burning, and none were serious. For cranberry, the NCCIH says it is generally thought to be safe, though very large amounts can cause stomach upset and diarrhea.
In the 2023 Cochrane review, stomach and bowel side effects were probably no more common with cranberry than with placebo or no treatment.
What should you not mix with D-mannose or cranberry?
The one interaction that health agencies flag is cranberry with the blood thinner warfarin. The NCCIH says there is conflicting evidence about whether the two interact, and advises anyone taking warfarin or any other medicine to talk with a health care provider before using cranberry. For D-mannose, published trials reported side effects poorly, so interaction data are thin.
The NCCIH also notes that cranberry appears safe during pregnancy and breastfeeding in the amounts commonly found in food, but the evidence is not conclusive for larger amounts. If you are pregnant, ask before taking either supplement.
Are cranberry pills better than cranberry juice?
Nobody knows yet. The 2023 Cochrane review said it is unclear whether cranberry juice and cranberry tablets differ in effect, because the certainty of the evidence was very low. It also found no clear difference in UTI risk between low, moderate and high doses of PACs, so no specific dose can be called the right one.
The NCCIH points out one practical issue: processing cranberries into products like tablets or capsules can reduce the concentration of PACs, which can reduce how effective a product might be. A label that states the amount of PACs per serving at least tells you what you are getting. That's the kind of open label we looked for in our UroFresh review, a supplement that lists both cranberry and D-mannose by the milligram.
What else helps prevent recurrent UTIs after menopause?
Vaginal estrogen is the option the AUA guideline singles out. For perimenopausal and postmenopausal women with recurrent UTIs, it says clinicians should recommend vaginal estrogen therapy to reduce the risk of future infections, if there is no contraindication. For women who drink less than 1.5 liters (50 ounces) a day, the guideline adds that increased water intake may be offered.
Both are conversations to have with your doctor, who can also check for other causes. If leaks or urgency are also part of the picture, our guide to pelvic floor exercises for women over 50 covers what the research says about them. Probiotics are another option women ask about, and our review of one women's probiotic looks at what its label and the studies show.
See a doctor if you notice…
- Burning or pain when you pee, or a sudden, frequent urge to go
- Fever, chills, or pain in your back or side
- Blood in your urine
- Symptoms that come back after treatment
- Two or more infections in six months
- Any UTI symptoms during pregnancy
Keep reading
- Pelvic Floor Exercises for Women Over 50: A Complete Guide
- How to Do Kegels Correctly for Women: A Step-by-Step Guide
- Why Do I Pee So Much at Night? Causes in Women and What Helps
- UroFresh Review: Simple Promise Label, Doses & Research
Frequently asked questions
Is it good to take D-mannose every day?
The best trial so far did not find a benefit. In a 2024 study in JAMA Internal Medicine, 598 women with recurrent UTIs took 2 grams of D-mannose or a placebo daily for six months, and the results were similar in both groups. The American Urological Association says D-mannose alone may not be effective for prevention.
How much cranberry do you need to prevent UTIs?
Nobody knows the best dose yet. The 2023 Cochrane review of 50 studies found no clear difference in UTI risk between low, moderate and high doses of proanthocyanidins (PACs), the active compounds in cranberry. The reviewers also said it is unclear whether cranberry juice and cranberry tablets work differently, because the evidence was very uncertain.
Can cranberry juice cure a UTI?
No. The National Center for Complementary and Integrative Health, part of the U.S. National Institutes of Health, states that cranberry is not recommended as a treatment for existing UTIs in any population. It also says not to use cranberry products instead of a proven treatment. Symptoms of an infection need a visit to your doctor.
Does cranberry work for everyone?
No. The 2023 Cochrane review found that cranberry products probably reduce UTIs in women with recurrent infections and in children. It found little or no benefit, based on low-certainty evidence, in elderly men and women living in care institutions, in pregnant women, and in adults whose bladders do not empty fully because of nerve problems.
How many UTIs count as recurrent?
The American Urological Association defines recurrent UTI as two episodes of acute bacterial cystitis within a six-month period sometime in the preceding year. The 2024 D-mannose trial used a similar rule: at least two UTIs in the last six months, or three in the last twelve months. Each one should be confirmed by your doctor.
Sources
- Hayward G, Mort S, Hay AD, et al. d-Mannose for Prevention of Recurrent Urinary Tract Infection Among Women: A Randomized Clinical Trial. JAMA Internal Medicine. 2024;184(6):619-628. doi:10.1001/jamainternmed.2024.0264. PMID 38587819.
- Williams G, Hahn D, Stephens JH, Craig JC, Hodson EM. Cranberries for preventing urinary tract infections. Cochrane Database of Systematic Reviews. 2023;4:CD001321. doi:10.1002/14651858.CD001321.pub6. PMID 37068952.
- Cooper TE, Teng C, Howell M, Teixeira-Pinto A, Jaure A, Wong G. D-mannose for preventing and treating urinary tract infections. Cochrane Database of Systematic Reviews. 2022;8:CD013608. doi:10.1002/14651858.CD013608.pub2. PMID 36041061.
- American Urological Association. Recurrent Uncomplicated Urinary Tract Infections in Women: AUA/CUA/SUFU Guideline. Published 2019, reviewed 2022, amended 2025. Checked October 3, 2026.
- National Center for Complementary and Integrative Health (NCCIH), U.S. National Institutes of Health. Cranberry: Usefulness and Safety. Last updated November 2024. Checked October 3, 2026.
Claire Donovan
I'm Claire Donovan, a 47-year-old woman who became much more interested in women's health after experiencing some of my own challenges with pelvic and urinary health.
I'm not a doctor or healthcare professional. I'm simply someone who has spent years researching these subjects, comparing information, reading scientific research, and looking for reliable answers from trusted and official sources.
My goal is simple: to make reliable information easier to understand and help women feel more informed about their own health. More about me.
Last updated: . Every figure was checked against the sources listed above on this date.
How this guide was made: it is based on a randomized clinical trial, two Cochrane reviews, a national urology guideline and a U.S. National Institutes of Health fact sheet, explained in plain language.
Medical note: this guide is general information and isn't medical advice. Medical disclaimer.