Cranberry

Best for

Reduce urinary tract infections

Proven strong benefit · 0.4–1000 g/day for 26–52 weeks · 5 meta-analyses , n=18.8k

33 papers · 3 claims · 79 outcomes scored · 3 positive

Outcomes

What cranberry actually does, by outcome

Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.

Outcome Effect size Evidence Dose Weeks Rank

Reduce urinary tract infections Proven strong benefit

Fewer infections, less antibiotic use, and a lower bacterial load.

12 meta-analyses n=19k 0.4–1000 g 26–52 wk

18707726·22305026·22811926·27787564 +8 more

large

12 meta-analyses n=19k Meta-analyzed I²=75%

0.4–1000 g

26–52 wk

—

Reduce recurrent UTIs in children Proven strong benefit

Breaks the cycle of repeat urinary infections in children prone to them.

11 meta-analyses n=18k 0.4–1000 mg 26–52 wk

18707726·22305026·22811926·23076891 +7 more

large

11 meta-analyses n=18k Meta-analyzed

0.4–1000 mg

26–52 wk

—

Reduce UTIs in high-risk groups Proven strong benefit

Fewer infections in care homes, pregnancy, cancer care, or nerve damage.

11 meta-analyses n=18k 0.4–1000 mg 26–52 wk

18707726·22305026·22811926·23076891 +7 more

large

11 meta-analyses n=18k Meta-analyzed

0.4–1000 mg

26–52 wk

—

Forms & standardisation

Juice, juice concentrate, capsules, and tablets all show up in the literature, but the signal comes from products that deliver a defined cranberry dose every day.1 On labels, look for a listed cranberry amount or a standardized extract rather than a vague berry blend, because the active dose varies a lot across products.1

Risk profile

Adverse events and known drug interactions

Safety events

serious adverse events (participants experiencing ≥1 SAE) severe

Suprapubic pain, dysuria, backache, cloudy urine and single vomit (possible pyelonephritis) moderate

Feeling unwell, ache in lower back moderate

General feeling unwell, backache, stomachache, headache and nausea (possible pyelonephritis) moderate

Minor adverse effects (gastrointestinal, vaginal, other; primarily constipation, heartburn, loose stool, vaginal itching/dryness, migraine) mild

rash mild

constipation mild

Felt sick (nausea) mild

Drug interactions

Simvastatin major increases concentration

Felodipine major increases concentration

Verapamil major increases concentration

Lovastatin major increases concentration

Warfarin major increases toxicity

Warfarin major increases effect

Tacrolimus moderate unknown

Nifedipine moderate increases concentration

Midazolam minor decreases concentration

Cyclosporine minor unknown

Co-studied with

Supplements that share evidence with cranberry

Lingonberry 3 shared outcomes · d=0.43

Frequently asked

Common questions

Does cranberry really reduce UTIs?

Yes. The best evidence shows fewer repeat urinary tract infections, especially in people with recurrent UTIs and other high-risk groups.¹

How long do you need to take cranberry?

Think months, not days. The positive trials ran about 26-52 weeks, so cranberry works like a daily background habit rather than a quick fix.¹

Why does cranberry seem to work better for some people?

The strongest results show up in people who keep getting UTIs, including children and other high-risk groups.¹ If you rarely get infections, the payoff drops fast.

What is cranberry doing in the body?

Its plant compounds make common UTI bacteria less able to cling to urinary tract surfaces, so they wash out more easily.¹

Track cranberry in the app

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Sources

1. Cranberries for preventing urinary tract infections (2012) ↑
2. Cranberries for preventing urinary tract infections (2012) ↑
3. Cranberries for preventing urinary tract infections (2012) ↑

Generated May 15, 2026