Last verified: today
Cranberry
Also known as: Vaccinium macrocarpon, American cranberry, cranberry extract, cranberry polyphenols, proanthocyanidins, PACs
Evidence under review. — Not yet rated
Fruit extract best known for reducing recurrent UTIs in women. Modest evidence for gut and cognitive benefits.
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What it does
Cranberry is a North American fruit rich in type A proanthocyanidins (PACs) — plant compounds that appear to stop bacteria like E. coli from sticking to the urinary tract wall. Clinical trials...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
36 mg/day type A proanthocyanidins (PACs) for UTI prevention; whole fruit powder doses vary by product
What the Science Says
Cranberry is a North American fruit rich in type A proanthocyanidins (PACs) — plant compounds that appear to stop bacteria like E. coli from sticking to the urinary tract wall. Clinical trials show whole cranberry powder can cut the risk of culture-confirmed urinary tract infections by roughly 50% in women with a history of recurrent UTIs over six months. Emerging research also suggests cranberry polyphenols may modestly support gut microbiota diversity and short-term memory, though these findings are preliminary.
What It Doesn't Do
Won't cure an active UTI — it's a prevention tool, not a treatment. No solid evidence it reliably improves mood, reduces anxiety, or fights depression. Not proven to prevent kidney stones despite popular belief. Evidence for benefits in children is thin and inconsistent. A multi-ingredient supplement blend (Paper 2) showed pregnancy-related benefits, but cranberry alone was not isolated as the cause.
Evidence-Based Benefits
Reduces recurrent UTI risk by ~50% in women with a history of frequent infections over 6 months.
Moderate EvidenceEffective at: Whole cranberry powder capsules; ~36 mg/day type A PACs
Supporting studies (click to view on PubMed):
Shifts gut bacteria composition and increases beneficial microbial metabolites in overweight adults.
Weak EvidenceEffective at: 54.5 mg/day total polyphenols (cranberry juice) for 6 weeks
Supporting studies (click to view on PubMed):
May improve short-term and phonological memory in healthy young adults after 12 weeks of daily use.
Weak EvidenceEffective at: Polyphenol-rich cranberry drink daily for 12 weeks
Supporting studies (click to view on PubMed):
Lowers daily cortisol output in healthy university students after 12 weeks of supplementation.
Weak EvidenceEffective at: Polyphenol-rich cranberry drink daily for 12 weeks
Supporting studies (click to view on PubMed):
Absorption & Bioavailability
Moderate — cranberry polyphenols reach the colon largely unmetabolized and are converted by gut bacteria into bioactive metabolites. Studies confirm measurable increases in serum and urinary metabolites (catechol-O-sulfate, 4-hydroxyhippuric acid) after consumption, indicating absorption occurs but varies by individual gut microbiome composition.
Red Flags to Watch For
- Cranberry products vary widely in PAC content — look for standardized extracts specifying at least 36 mg/day of type A proanthocyanidins, not just 'cranberry extract'
- Cranberry juice cocktails are high in sugar and may contain very little actual PAC — juice is not equivalent to standardized supplements
- Pharmacists surveyed showed significant knowledge gaps around safe dosing, drug interactions, and use in pregnancy/lactation — consult a healthcare provider before use if pregnant or on blood thinners
- Cranberry is generally less effective than antibiotics for UTI prevention and should not replace prescribed treatment for active infections
- Kidney stone patients commonly use cranberry extract despite unknown and potentially harmful effects on stone pathophysiology — check with your urologist first
Products Containing Cranberry
See how Cranberry is used in these analyzed products:
Renew Life 3-Day Cleanse
Supplement
Texas SuperFood Original Capsules
Supplement
Renew Life 3 Day Cleanse Total Body Reset
Supplement
HUM Nutrition Private Party
Supplement
Private Party Probiotic by HUM
Supplement
Smartvita Women's Total Synergy Multivitamins
Supplement
Frequently Asked Questions
What does Cranberry do?
Fruit extract best known for reducing recurrent UTIs in women. Modest evidence for gut and cognitive benefits.
What is the effective dose of Cranberry?
36 mg/day type A proanthocyanidins (PACs) for UTI prevention; whole fruit powder doses vary by product
Is Cranberry safe?
Cranberry products vary widely in PAC content — look for standardized extracts specifying at least 36 mg/day of type A proanthocyanidins, not just 'cranberry extract'
What doesn't Cranberry do?
Won't cure an active UTI — it's a prevention tool, not a treatment.
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-07-05