Cranberry: it's about adhesion, not acidity.
For decades, the popular theory was that cranberry juice made urine more acidic and hostile to bacteria. That isn't thought to be the main way it works.9
Cranberries contain compounds called proanthocyanidins (PACs), specifically A-type PACs. In laboratory studies, these interfere with E. coli's ability to stick to the cells lining the urinary tract, while the B-type PACs found in foods such as grapes had little or no effect.1
E. coli have hair-like projections called fimbriae that work a bit like Velcro, attaching to sugar molecules on the urinary tract wall. Bacteria that can't attach are more easily flushed out with urine.1
The clinical evidence: A 2023 Cochrane review of 50 trials found that cranberry products reduced the risk of repeat symptomatic UTIs by about a quarter in women with recurrent UTIs, by about half in children, and by about half in people at risk after medical procedures.2 They showed little or no benefit in older people living in care homes, pregnant women or people with bladder-emptying problems.2 US urology guidelines now say clinicians should offer cranberry as a prevention option.3
What to look for in cranberry products:
- PAC content: Many providers recommend a supplement standardized to at least 36 mg of PACs a day.3 A 2024 analysis of trials found a benefit at 36 mg or more but not at lower doses,4 though the Cochrane review didn't find a clear difference between doses,2 so the ideal amount isn't settled.
- Extracts vs. juice: Cranberry juice drinks are usually sweetened and vary in PAC content, so a standardized supplement makes the dose more predictable.
- A-type PACs: Look for products that state their cranberry PAC content.1
D-mannose: a different approach to the same goal.
D-mannose is a simple sugar found in small amounts in fruits such as cranberries, apples and oranges. Much of it passes into the urine rather than being used for energy.
Its proposed mechanism: the fimbriae that E. coli use to attach to the urinary tract wall bind to mannose. When D-mannose is in the urine, it can bind to those fimbriae instead, so bacteria may be flushed out rather than taking hold.5
The clinical evidence: A 2014 trial of 308 women found fewer repeat UTIs with 2 g of D-mannose a day than with no prevention, at a rate similar to a low-dose antibiotic.6 That trial had no placebo group, though. A larger double-blind trial published in 2024, with 598 women, compared D-mannose with a placebo and found no meaningful difference in UTIs. Its authors concluded that D-mannose shouldn't be recommended for this group.7 A 2022 Cochrane review also found too little evidence to support or rule out its use,8 and the 2025 US urology guideline says D-mannose on its own may not be effective.3
If you're considering D-mannose:
- It's generally well tolerated, but current evidence doesn't support relying on it for prevention.
- It doesn't treat an active UTI, so see a provider if you have symptoms.
Cranberry and D-mannose together:
Because the two are thought to act on bacterial adhesion in different ways, they're often sold together. There isn't strong evidence yet that combining them works better than cranberry alone, so if you're choosing one, cranberry has the stronger research behind it.2,3
Where V On The Go fits:
Biolouve's V On The Go wipes include cranberry and D-mannose among their ingredients, alongside chamomile and calendula. The research above is about supplements taken by mouth at measured doses. A wipe used on the outside of the body works differently: V On The Go is made for gentle freshening and comfort, not for preventing UTIs.
What cranberry and D-mannose can't do:
Neither treats an active UTI. Once bacteria have multiplied in the bladder and caused symptoms, you'll usually need medical treatment.9 Always see a provider if you have UTI symptoms.
Safety:
Both are generally well tolerated by most adults. Things to know:
- Cranberry: The evidence on whether cranberry interacts with the blood thinner warfarin is conflicting, so talk with your provider if you take it.9
- D-mannose: It's a sugar, so people with diabetes may want to check with their provider first.
- Both can cause mild stomach upset in some people.
Cranberry has been linked to urinary health for more than a century, and D-mannose has become a popular supplement over the past two decades. But how they work is often misunderstood: cranberry doesn't work by acidifying urine, and D-mannose isn't the same thing as cranberry sugar. Here's what the research shows for each, including where the evidence is strong and where it's weaker than its reputation.
Quick answer
Cranberry and D-mannose are both thought to stop E. coli from sticking to the urinary tract wall, rather than changing urine pH. Cranberry has the stronger evidence, and US urology guidelines now recommend it as a prevention option. D-mannose looked promising in an early trial, but a larger 2024 trial found no benefit. Neither treats an active infection.
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For everyday external hygiene. Not intended to prevent, treat, or cure UTIs or any medical condition.
| Cranberry (PACs) | D-mannose | |
|---|---|---|
| How it works | A-type proanthocyanidins are thought to block E. coli from attaching | Binds E. coli so it may be flushed out |
| Best form | Supplement standardized for PACs, more predictable than juice | Powder or capsule |
| Evidence | Moderate: a Cochrane review and US guidelines support it as an option | Mixed: a large 2024 trial found no benefit |
| Role | Prevention support, not treatment | Not recommended for prevention on current evidence |
Key Takeaways
- Cranberry's A-type PACs are thought to stop E. coli sticking to the urinary tract wall; they don't work by acidifying urine
- A 2023 Cochrane review found cranberry cut repeat UTIs by about a quarter in women with recurrent infections
- US urology guidelines now recommend cranberry as a prevention option, often at 36 mg of PACs a day
- D-mannose looked promising early, but a large 2024 placebo-controlled trial found no benefit
- The research is on oral supplements; a topical wipe like V On The Go is for freshness, not UTI prevention
- Neither cranberry nor D-mannose treats an active UTI, so see a provider for symptoms
Sources
- Howell AB, Reed JD, Krueger CG, et al. A-type cranberry proanthocyanidins and uropathogenic bacterial anti-adhesion activity. Phytochemistry. 2005;66(18):2281-2291.
- Williams G, Stothart CI, Hahn D, et al. Cranberries for preventing urinary tract infections. Cochrane Database Syst Rev. 2023;11:CD001321.
- American Urological Association, Canadian Urological Association and Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction. Recurrent Uncomplicated Urinary Tract Infections in Women: AUA/CUA/SUFU Guideline (amended 2025).
- Xiong Z, Gao Y, Yuan C, Jian Z, Wei X. Preventive effect of cranberries with high dose of proanthocyanidins on urinary tract infections: a meta-analysis and systematic review. Front Nutr. 2024;11:1422121.
- Scaglione F, Musazzi UM, Minghetti P. Considerations on D-mannose mechanism of action and consequent classification of marketed healthcare products. Front Pharmacol. 2021;12:636377.
- 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.
- Hayward G, Mort S, Hay AD, et al. d-Mannose for prevention of recurrent urinary tract infection among women: a randomized clinical trial. JAMA Intern Med. 2024;184(6):619-628.
- Cooper TE, Teng C, Howell M, et al. D-mannose for preventing and treating urinary tract infections. Cochrane Database Syst Rev. 2022;8:CD013608.
- National Center for Complementary and Integrative Health (NIH). Cranberry.