Cranberry extract is a supplement made from the North American cranberry, promoted mainly to prevent urinary tract infections (UTIs). A 2023 Cochrane review found cranberry products reduce the risk of UTIs in women with repeat UTIs, children, and people prone to UTIs after medical procedures, but it is not a treatment for an existing infection.
Also known as: cranberry extract, Vaccinium macrocarpon, proanthocyanidins.
The Cochrane review could not tell whether juice and tablets or different amounts of proanthocyanidins (PACs) differ in effect (Williams 2023), so we do not list an amount.
It is sold in the US as a dietary supplement. Under the 1994 dietary supplement law (DSHEA), FDA does not approve dietary supplements before they are marketed, and the maker, not FDA, is responsible for safety and labeling. NCCIH says that since 2020 FDA has allowed labels to say there is "limited" evidence that daily cranberry supplements may reduce the risk of repeat UTIs in healthy women.
What studies show: a 2023 Cochrane review of 50 trials (8,857 people) found cranberry products reduced the risk of symptomatic, culture-confirmed UTIs by about 30% overall (moderate certainty). The benefit held in women with repeat UTIs, children, and people prone to UTIs after a medical procedure, but there may be little or no benefit in older adults in care homes, pregnant women, or people with bladder emptying problems (Williams 2023). NCCIH says cranberry is not recommended as a treatment for an existing UTI, and that processing into tablets or capsules can lower the PAC content.
Safety, per NCCIH: cranberry by mouth is generally thought to be safe, but very large amounts can cause stomach upset and diarrhea, especially in young children. Evidence is conflicting on whether it interacts with warfarin. Do not use it instead of proven treatment if you think you have a UTI.
We could not find a single published half-life or time to peak for cranberry that applies to a supplement dose, so we do not list one. Plant extracts are mixtures of many compounds, so no single figure would describe them.
How Dose Track handles peptides · Reconstitution calculator · Half-life calculator