Identity & origin
BOTANICAL IDENTITY
The right name is the first step.
Documentary entry on cranberry, the part studied and the limits of knowledge.
Also known as: cranberry
Vaccinium macrocarpon is not bilberry, Vaccinium myrtillus.
An illustration is not enough to identify a plant for consumption. Do not forage for a species based solely on this profile.
Uses & evidence
UNDERSTANDING THE USES
Properties & uses.
Recurrent urinary complaints
Some studies suggest a preventive benefit, particularly in women with recurrent infections; the effect is not identical in all populations.
A human study may be positive, negative or inconclusive. Read the findings, preparation and limitations.
Read the sourceThe traditional uses described are not clinical proof of effectiveness. Evidence for one preparation cannot automatically be applied to another.
Precautions before use
BEFORE ANY USE
Precautions & contraindications.
This guidance does not cover every individual situation. Missing information is not a guarantee of safety.
Contraindications & precautions
- Source-listed contraindicationFruit allergy. Combining medicinal preparations with warfarin or tacrolimus is contraindicated by the EMA.Source
- Source-listed contraindicationIn kidney disease with recurrent urinary infections, self-medication with these preparations is contraindicated; medical supervision is required.Source
- PrecautionHistory of urinary stones: have the exact concentrate reviewed. Fever, flank pain or blood in urine requires assessment; cranberry does not treat an existing infection.Source
Medicine interactions
- Reported interactionWarfarin: elevated INR and bleeding have been reported; experimental and clinical findings conflict. Nevertheless, the EMA framework contraindicates the combination.Source
- Reported interactionTacrolimus: reduced blood concentration was reported in one renal transplant case and reversed after cranberry withdrawal. The EMA contraindicates the combination; mechanism and frequency remain uncertain.Source
“Reported” does not prove causality; “possible” may reflect indirect evidence. “None reported” means none in the cited source, not that all combinations have been studied. Do not stop a prescribed treatment based on this profile.
Adverse effects
- Digestive tolerability and other risks to check depending on the product.
Pregnancy & breastfeeding
Do not self-treat urinary symptoms during pregnancy. Food quantities and concentrated doses are not equivalent; available data do not support recommending medicinal use during pregnancy or breastfeeding.
SourceChildren & adolescents
Medicinal preparations are not recommended below 18 years under the EMA framework because data are insufficient. Paediatric trials exist but do not validate all products or a home dose.
SourceIf symptoms persist, worsen or are unusual, consult a healthcare professional. In an emergency, contact the emergency services.
Available evidence
EXPLORE THE EVIDENCE
The available evidence.
Cranberry is studied mainly to limit certain recurrences of urinary tract infection, not to treat an infection already present. The central hypothesis concerns bacterial adhesion to urinary surfaces: preventing attachment differs from killing bacteria. Human results involve varying populations and products. Juice, a dry extract and a powder therefore do not automatically offer the same effect, even if their labels name the same fruit.
Constituents to know.
Their presence and quantity depend on the plant part and preparation.
- Proanthocyanidins
- Polyphenols involved in anti-adhesion research; their content and profile depend on the product and its processing.Read the reference
Bacterial adhesion
Laboratory tests and tests on urine collected after consumption observe a reduction in certain types of bacterial adhesion. This intermediate result does not guarantee fewer infections.
Laboratory or animal observation. A human benefit cannot be inferred from this finding alone.
Read the referenceRecurrent urinary complaints
Some studies suggest a preventive benefit, particularly in women with recurrent infections; the effect is not identical in all populations.
A human study may be positive, negative or inconclusive. Read the findings, preparation and limitations.
Read the referenceLimitations to keep in mind.
A recurrence must first be medically identified. The EMA report recognizes a contraindication to combining medicinal preparations with warfarin or tacrolimus; people concerned must seek advice before use.
Studies, findings & limitations
THE RESEARCH
What the research shows.
A laboratory or animal result alone does not demonstrate a benefit in humans. Each result must be read alongside the preparation studied and its limitations.
Clinical results dependent on the product
A human study may be positive, negative or inconclusive. Read the findings, preparation and limitations.
- Type of research
- EMA report and NCCIH summary of human trials.
- Preparation concerned
- Vaccinium macrocarpon juices, beverages and dry preparations.
- Observed results
- Studies include favorable and negative results; NCCIH recognizes a possible benefit in certain recurrences.
- Limitations to consider
- Different definitions of infection, variable composition, withdrawals and heterogeneous populations complicate comparison.
What can we take from this?
Cranberry does not replace treatment of an ongoing infection. Absence of burning does not prove absence of infection; fever, lower back pain or kidney disease require assessment. Warfarin data are contradictory, which does not cancel the regulatory precaution.
Documentary review dated 09/10/2026. The references remain available to check the context.
Sources & last review
CHECKING REFERENCES
Sources for this profile.
- EMA — Vaccinii macrocarpi fructus: dossier and documentsAccessed on 09/10/2026
- EMA — scientific assessment report: Vaccinium macrocarponAccessed on 09/10/2026
- NCCIH — Cranberry: Usefulness and SafetyAccessed on 09/10/2026
Image: Photo by Keith Weller · Public domain. View the original image and its licence. Image resized and converted to WebP.