Cranberry Extract

Also known as: cranberry, vaccinium macrocarpon, cranberry concentrate, PAC

Grade B — Moderate Evidenceherbalurinary
500–500 mgOnce or twice daily; standardized to 36mg proanthocyanidins (PAC)

Concentrated source of proanthocyanidins (PACs) that prevent bacterial adhesion to urinary tract walls. Good evidence for preventing recurrent UTIs in women. Extract form (36mg PAC) is more effective and practical than juice. Safe for long-term use.

🛡️Immunity🦠Gut Health
Last reviewed: 2026-03-12

Quick Facts

Evidence

Grade B

Studies

1

Interactions

1

Forms

1

Evidence Rating: Grade B — Moderate Evidence

Some RCTs with positive results, or strong observational evidence. More research may refine our understanding.

Interaction Warnings

WarfarinModerate

Cranberry may increase warfarin effect via CYP2C9 inhibition — monitor INR.

Important Notes

  • Standardized to PAC (proanthocyanidin) content — 36mg/day is the studied dose
  • Juice is less effective than concentrated extract due to sugar content and lower PAC
  • Primarily studied in women for recurrent UTI prevention
  • Not a treatment for active UTIs — see a doctor for acute infections

Clinical Evidence (1 study)

Cranberries for preventing urinary tract infections

Jepson RG et al. (2012) — Cochrane Database Syst Rev

Cranberry products significantly reduced UTI incidence in women with recurrent infections

View on PubMed

Alternatives to Consider

These supplements target similar goals and may be worth considering alongside or instead of Cranberry Extract.

D-Mannose

Grade B

Natural sugar that prevents E. coli from adhering to urinary tract walls. As effective as low-dose antibiotics for preventing recurrent UTIs with far fewer side effects. Very safe and well-tolerated.

🛡️ Immunity🦠 Gut Health

Oregano Oil

Grade C

Potent antimicrobial herb with broad-spectrum activity against bacteria, fungi, and parasites. Active compound carvacrol shows strong in vitro effects. Best used short-term for acute gut or immune challenges. Prolonged use may harm beneficial gut bacteria. Cycle strictly.

🛡️ Immunity🦠 Gut Health

Andrographis

Grade B

Ayurvedic and Traditional Chinese Medicine herb with strong evidence for reducing severity and duration of upper respiratory infections. Active compound andrographolide has anti-inflammatory and immune-modulating properties. Best used acutely at illness onset.

🛡️ Immunity

Related Supplements

D-Mannose

Grade B — Moderate Evidence

Natural sugar that prevents E. coli from adhering to urinary tract walls. As effective as low-dose antibiotics for preventing recurrent UTIs with far fewer side effects. Very safe and well-tolerated.

Oregano Oil

Grade C — Preliminary

Potent antimicrobial herb with broad-spectrum activity against bacteria, fungi, and parasites. Active compound carvacrol shows strong in vitro effects. Best used short-term for acute gut or immune challenges. Prolonged use may harm beneficial gut bacteria. Cycle strictly.

NAC (N-Acetyl Cysteine)

Grade B — Moderate Evidence

Precursor to glutathione (master antioxidant). Strong evidence for respiratory health, liver support, and psychiatric conditions.

Probiotics

Grade B — Moderate Evidence

Beneficial bacteria for gut health. Strain selection matters — L. rhamnosus GG, B. infantis 35624, and S. boulardii are best-studied.

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⚕️ Important Disclaimer

This information is for educational purposes only. It is not medical advice. Always consult a healthcare provider before starting any supplement regimen, especially if you take medications or have health conditions.

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