Cranberry
Cranberry is an evergreen shrub that grows in wet habitats in the Northeastern and North Central parts of North America, and MSK says it is grown in North America and Europe. Today it is commonly promoted for urinary tract infections (UTIs) and recurrent UTIs, and MSK says the juice extract is marketed as a dietary supplement for urinary tract health.
Where to get it
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Active compounds & mechanisms
Key compounds: Proanthocyanidins (PACs)
It's thought that the proanthocyanidins (PACs) present in cranberries prevent bacteria from sticking to the bladder wall. Processing cranberries into various products, like tablets or capsules, can reduce the concentration of PACs.
Research & evidence
Strong support Some support Weak or no supportColours show how well the sources back each point. The reason is next to each one.
NCCIH says cranberry products may decrease the overall risk of symptomatic, recurrent UTIs in women by 25 percent.
Limited evidenceSome support. The source hedges (“may” or “associated with”)
Study details
In general, cranberry products may decrease the overall risk of symptomatic, recurrent UTIs in women by 25 percent.
Source: NCCIH, Cranberry (Last Updated November 2024), Research Findings View source
NCCIH says the effectiveness of cranberry is still in question because of inconsistent findings.
Mixed evidenceSome support. Results are mixed
Study details
the effectiveness of cranberry is still in question because of inconsistent findings.
Source: NCCIH, Cranberry (Last Updated November 2024), Research Findings View source
Cranberry may assist in preventing symptomatic UTIs in some women.
Limited evidenceSome support. Shown only in certain groups, uses, strains or doses
Study details
While cranberry may assist in preventing symptomatic UTIs in some women,
Source: NCCIH, Cranberry (Last Updated November 2024), Research Findings View source
Some research on cranberry for the prevention of UTIs isn't of high quality.
Limited evidenceSome support. Reviewers rated the certainty low
Study details
However, some research isn't of high quality.
Source: NCCIH, Cranberry (Last Updated November 2024), Research Findings View source
Studies in higher-risk populations have had inconsistent results.
Mixed evidenceSome support. Results are mixed
Study details
have had inconsistent results.
Source: NCCIH, Cranberry (Last Updated November 2024), Research Findings View source
Cranberry isn't recommended as a treatment for existing UTIs in any population.
Not supported by current evidenceWeak or no support. Trials found no clear benefit
Study details
it isn't recommended as a treatment for existing UTIs in any population.
Source: NCCIH, Cranberry (Last Updated November 2024), Research Findings View source
MSK says cranberry juice or extracts may be helpful for UTIs in limited populations.
Limited evidenceSome support. Shown only in certain groups, uses, strains or doses
Study details
Cranberry juice or extracts may be helpful for urinary tract infections (UTIs) in limited populations
Source: MSK About Herbs, Cranberry (updated February 5, 2021), Research Findings View source
MSK says there is not enough evidence to recommend cranberry for UTI prevention.
Limited evidenceSome support. Reviewers rated the certainty low
Study details
there is not enough evidence to recommend it for UTI prevention.
Source: MSK About Herbs, Cranberry (updated February 5, 2021), Research Findings View source
MSK says studies of cranberry juice for recurrent UTIs have been mixed.
Mixed evidenceSome support. Results are mixed
Study details
Studies of cranberry juice for recurrent UTIs have also been mixed.
Source: MSK About Herbs, Cranberry (updated February 5, 2021), Research Findings View source
MSK says a systematic review determined that cranberry juice was more effective than capsules or tablets.
Limited evidenceSome support. Based mainly on one review or trial
Study details
Overall, a systematic review determined that cranberry juice was more effective than capsules or tablets.
Source: MSK About Herbs, Cranberry (updated February 5, 2021), Research Findings View source
MSK says studies suggest cranberry juice may help prevent or suppress H. pylori infection.
Limited evidenceSome support. The source hedges (“may” or “associated with”)
Study details
Studies suggest cranberry juice may help prevent or suppress H. pylori infection.
Source: MSK About Herbs, Cranberry (updated February 5, 2021), Research Findings View source
Lab studies suggest activity against several types of cancer cells.
Preclinical onlyWeak or no support. Mostly lab or animal studies
Study details
Although lab studies suggest activity against several types of cancer cells,
Source: MSK About Herbs, Cranberry (updated February 5, 2021), Research Findings View source
Dosage
| Form | Amount |
|---|---|
| Any form | No standard dose is listed by our sources. |
Side effects
Well documented Reported (case reports, anecdotal or one study) None reportedThe circle shows how well documented an effect is, not how serious it is. A rarely reported effect can still be serious, so always read ‘When to stop’.
| Effect | Frequency | When to stop |
|---|---|---|
| Stomach upset and diarrhea (in very large amounts)Well documentedListed plainly by NIH, MSK or LiverTox | Seen with very large amounts; MSK links 3 cups of cranberry juice daily to gastrointestinal upset | Stop and talk to a doctor if you notice any unexpected or concerning symptoms. |
Safety & interactions
Safety
Cranberry taken by mouth is generally thought to be safe. If consumed in very large amounts, it can cause stomach upset and diarrhea. MSK says that in people who are prone to kidney stones, regular use of cranberry should be avoided. There is conflicting evidence about whether cranberry interacts with the blood thinner warfarin, and MSK reports case reports of bleeding and death in 2 elderly patients who used cranberry juice and warfarin. If you take warfarin or any other medicine, talk with your health care provider before using cranberry.
Contraindications
MSK says that in people who are prone to kidney stones, regular use of cranberry should be avoided. If you take warfarin or any other medicine, NCCIH advises talking with your health care provider before using cranberry (see Drug interactions). Some studies of cranberry use during pregnancy or while breastfeeding suggest it is safe, but NCCIH says that if you're considering using cranberry while pregnant or breastfeeding, you should consult your health care provider.
Drug interactions
NCCIH says there is conflicting evidence about whether cranberry interacts with the anticoagulant (blood thinner) warfarin. MSK reports case reports of bleeding and death in 2 elderly patients who used cranberry juice and warfarin. If you take warfarin or any other medicine, talk with your health care provider before using cranberry.
MSK says serum levels of tacrolimus dropped when taken with cranberry extract.
MSK says cranberry may increase the risk of side effects for UGT substrate drugs.
Established: stated plainly by an authoritative source. Documented: supported by case reports or trial data. Theoretical: based on mechanism, animal data, or a cautious listing. Always check with your pharmacist or prescriber.
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