Cranberry for UTI: Efficacy, Dose, Side Effects, & Long-term Use
Our content is not intended nor recommended as a substitute for medical advice by your doctor. Use for informational purposes only.
Cranberry has been studied for decades for the prevention and treatment of UTIs. In this article, I will summarize the evidence, efficacy, indications, dosing, and long-term effects of cranberry on patients with UTI.
|BRAND NAMES||AZO Cranberry, Nature Made, Nature’s bounty, Cystex, American cranberry, CranRx, etc.|
|INDICATIONS||– Prevention of UTI recurrence (No benefit if you already have UTI).
– Urine Deodorizer (in patients with incontinence).
|OTHER POTENTIAL BENEFITS||https://www.mountsinai.org/health-library/herb/cranberry for:
– H. Pylori infection (stomach ulcers).
– Reduce cancer risk and growth.
– Fight viruses.
– Inhibit bacterial illnesses.
|EFFICACY||It may help prevent recurrent UTIs in women with a previous UTI, But the scientific evidence is limited.
Efficacy also varies by dose, formula, and brand.
|LACTATION||Limited data, but generally allowed (https://www.ncbi.nlm.nih.gov/books/NBK501837/).|
|PREGNANCY||Limited data. It is generally allowed. However, ask your doctor first.|
|FORMS||– Pills and Capsules.
– Juice (fresh and frozen) and juice cocktail.
– Pure Juice (but very sour).
|DOSE||– Pills/capsules: 400 mg twice daily.
– Juice mixes: 10-16 Fl Oz per day
– Pure juice: 15 mL twice per day.
Table of Contents
 Indications (Uses).
- Cranberry juice and supplements are indicated to prevent recurrent urinary tract infections (UTIs).
- It is NOT indicated for the treatment of UTI.
- Decrease Urine odor in patients with urinary incontinence.
Cranberry is a very well-known supplement that is used in urinary tract infections. Cranberry doesn’t treat UTIs that is already happened, nor replace the role of antibiotics.
Cranberry is used as a prophylaxis against recurrent urinary tract infection (UTI) in females who previously had UTI.
Cranberry can also decrease UTI symptoms by decreasing the inflammation and immune response to the invading bacteria (reference)
Other proposed benefits (but not yet approved for use in these conditions:
- H. Pylori infection (stomach ulcers).
- Reduce cancer risk and growth.
- Fight viruses.
- Inhibit bacterial illnesses.
- Fight fungal infections such as candida.
 How does Cranberry work for UTI Prevention?
Cranberry may prevent the recurrence of UTI by (reference):
- Proanthocyanidins (PACs) and their metabolites such as phenyl propionic acid).
- Organic acids such as malic, quinic, and shikimic acid.
- Its Vitamin C (ascorbic acid) content.
- Its low P.H. (acidity) may reach 2.5.
- Complex carbohydrates and sugars.
The cranberry’s unique mixture of sugars, organic acids, vitamin C, and D-mannose, as well as its low Ph, helps your body to fight against UTIs.
These compounds may help prevent UTIs by:
- Preventing the bacteria from adhering to the urinary tract lining cells (urothelial cells).
- Cranberry compounds are consumed by the gut microbiota producing beneficial effects on immunity. Some studies assume that gut microbiota may play a role in immunity and preventing UTIs.
- Cranberries may prevent temporary colonization of the pathologic bacteria in the colon (the source of UTI is colon bacteria) by promoting beneficial bacteria.
Some studies proposed that combining cranberry and probiotics may be more effective in preventing recurrent UTIs in women.
 Efficacy of Cranberry against antibiotics in preventing UTI.
- One meta-analysis of 9 studies found that people who take cranberry are 38% less likely to have UTIs (Odds Ratio is 0.62).
- In the same meta-analysis, cranberry was found even more effective for preventing RECURRENT UTI (people who take cranberry had 47% less risk.
- However, Uptodate.com criticizes this meta-analysis as it ignored other important clinical trials and several other statistical and study design issues limiting its value.
- On the other hand, another meta-analysis concluded that cranberry doesn’t reduce the risk of symptomatic or recurrent UTIs.
The scientific evidence is limited. However, some people may benefit from cranberry products in preventing the recurrence of UTI.
 Formula and doses.
Clinical studies didn’t suggest a specific dose, frequency, or duration for taking cranberries. Always follow the recommended dosing by the brand manufacturers.
A. cranberry pills and capsules.
The most famous cranberry supplement is AZO cranberry ®. It is available in:
- Gummies (with natural mixed-berry flavor).
A single caplet contains about 500 mg or cranberry extract. You can take two caplets with water (either in the morning or at night).
ASO cranberry caplets and gummies also contain vitamin C and probiotics.
B. Cranberry juice mixes.
Cranberry juice mixes contain 26% cranberry juice. You can take 10-16 Oz/per day.
C. Pure cranberry juice
Pure cranberry juice is also available. You can take 15 mL (around 0.5 Fl Oz) twice daily.
 Side effects.
Cranberry is considered a dietary supplement that is generally safe for use with minimal drug interactions.
Minor side effects and limitations of its use include:
- Increased caloric intake (risk of weight gain, elevated blood sugar), particularly with sweetened cranberry juice.
- Elevation of blood glucose (cranberry juice may be unsuitable for those with diabetes mellitus.
- Heartburn (with cranberry juice).
- It may increase the risk of kidney stones due to high oxalate content.
 Safety in Long-Term Use.
Cranberry is a natural product that is generally safe for use in the long term. However, it is recommended to take tablets or capsules if you plan to take them long-term.
This is because juice (especially sweetened, high-calorie cranberry juice) may be unsuitable for long-term use due to side effects such as high calories and effects on blood sugar.
- Written by a doctor.
MD, Internal Medicine and Nephrology specialist.
Dr. Esraa A. MagidAuthor