Cranberry (Vaccinium macrocarpon)

Herbal preparation for recurrent urinary tract infection prevention. In EU – traditional herbal medicinal product (EMA HMPC). AEMPS does not register as medicine; sold as supplement

ATC code: A11JA-CRANBERRY (Cranberry (Vaccinium macrocarpon))

Brand names – supplements

Now Cranberry, Cysticlean, Solgar Cranberry Extract, AZO Cranberry

Supplements are not tested in clinical trials and are not registered as medications.

Mechanism of action

Cranberry fruits contain type A proanthocyanidins (PAC), phenolic acids (chlorogenic, benzoic), flavonoids (quercetin, myricetin) and organic acids (quinic, citric). Main mechanism – type A proanthocyanidins bind E. coli fimbriae (especially PapG II type P fimbriae), blocking bacterial adhesion to uroepithelium. Standardised products contain 36 mg PAC per dose. PAC oral bioavailability is low, but effective urine concentration is reached in 4-8 hours. HMPC 2017 recognises cranberry as a traditional herbal medicinal product for recurrent UTI prevention. Cochrane 2023 updated the systematic review and confirmed moderate cranberry effect in women with recurrent UTIs.

Indications

Urinary tract infection

Adjunct

Cranberry is one of the few herbal preparations with relatively convincing evidence in recurrent urinary tract infection (UTI) prevention in women. Cochrane 2023 (Williams) updated systematic review of 50 RCTs in 9000 participants: cranberry products (standardised to 36 mg PAC × 1-2 times daily) reduced recurrent UTI frequency in women by 30% (NNT 8-13). HMPC 2017 recognises cranberry as a traditional herbal medicinal product for recurrent UTI prevention. EAU 2024 and AUA/CUA/SUFU 2022 list continuous or post-coital antibiotic prophylaxis (nitrofurantoin 50-100 mg, co-trimoxazole, fosfomycin) first-line for recurrent uncomplicated UTI in women; cranberry is additional option for patient preference and long-term antibiotic intolerance. For established UTI cranberry is ineffective.

Sources

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Safety

Contraindications

Known cranberry hypersensitivity
Warfarin and other coumarin anticoagulant therapy (proven drug interaction, raises INR)
Oxalate kidney stones (cranberry contains oxalates)
PPI and H2-blocker therapy (theoretical PAC efficacy reduction via acidity change)

Serious adverse effects

Bleeding complications in warfarin patients (published cases of INR rise to 6-8)
Nephrolithiasis (oxalate stones) with prolonged high doses
Allergic reactions (rare)

Common adverse effects

Nausea and abdominal pain (at large concentrated juice doses)
Diarrhoea
Urine colour change (reddish)

PregnancyFDA N

Cranberry as food is safe in pregnancy. Standardised supplement forms (36 mg PAC) have not been systematically studied in pregnancy RCTs. EMA HMPC 2017 lists pregnancy as cautious use. Concentrated juice and capsules in pregnancy under medical supervision.

Breastfeeding

Cranberry as food is compatible with lactation. Concentrated supplement forms in lactation under medical supervision.

Calculate RID

Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.

Frequently asked

What is Cranberry (Vaccinium macrocarpon) used for?

Cranberry (Vaccinium macrocarpon) is evaluated for the following indications with varying evidence strength: Urinary tract infection (evidence tier C). See the full indication matrix with dosing and citations above on this page.

What are the side effects of Cranberry (Vaccinium macrocarpon)?

Common side effects of Cranberry (Vaccinium macrocarpon) (≥ 1 in 100): Nausea and abdominal pain (at large concentrated juice doses), Diarrhoea, Urine colour change (reddish). See the Safety section for uncommon and serious reactions.

Is Cranberry (Vaccinium macrocarpon) safe during pregnancy?

FDA category N. Cranberry as food is safe in pregnancy. Standardised supplement forms (36 mg PAC) have not been systematically studied in pregnancy RCTs. EMA HMPC 2017 lists pregnancy as cautious use. Concentrated juice and capsules in pregnancy under medical supervision.

Is Cranberry (Vaccinium macrocarpon) compatible with breastfeeding?

Cranberry as food is compatible with lactation. Concentrated supplement forms in lactation under medical supervision.

Who should not take Cranberry (Vaccinium macrocarpon)?

Cranberry (Vaccinium macrocarpon) is contraindicated in: Known cranberry hypersensitivity; Warfarin and other coumarin anticoagulant therapy (proven drug interaction, raises INR); Oxalate kidney stones (cranberry contains oxalates); PPI and H2-blocker therapy (theoretical PAC efficacy reduction via acidity change). Full list in the Safety section.

Mechanism of action

Indications

Urinary tract infection

Adjunct

Sources

Safety

Contraindications

Known cranberry hypersensitivity
Warfarin and other coumarin anticoagulant therapy (proven drug interaction, raises INR)
Oxalate kidney stones (cranberry contains oxalates)
PPI and H2-blocker therapy (theoretical PAC efficacy reduction via acidity change)

Serious adverse effects

Bleeding complications in warfarin patients (published cases of INR rise to 6-8)
Nephrolithiasis (oxalate stones) with prolonged high doses
Allergic reactions (rare)

Common adverse effects

Nausea and abdominal pain (at large concentrated juice doses)
Diarrhoea
Urine colour change (reddish)

PregnancyFDA N

Breastfeeding

Cranberry as food is compatible with lactation. Concentrated supplement forms in lactation under medical supervision.

Calculate RID

Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.

Frequently asked

What is Cranberry (Vaccinium macrocarpon) used for?

What are the side effects of Cranberry (Vaccinium macrocarpon)?

Is Cranberry (Vaccinium macrocarpon) safe during pregnancy?

Is Cranberry (Vaccinium macrocarpon) compatible with breastfeeding?

Cranberry as food is compatible with lactation. Concentrated supplement forms in lactation under medical supervision.

Who should not take Cranberry (Vaccinium macrocarpon)?