Cranberry Forte 50,000mg 90 Capsules

Cranberry is one of the few herbal products with a large, consistent evidence base, and also one where the pack tells you least about what you're buying. So here's the triage our naturopaths run.

A good fit if

• You get urinary infections repeatedly and want something preventive
• You're buying for a child, where the pooled effect was largest
• You'll look for a declared proanthocyanidin figure rather than a fresh-fruit-equivalent number
• You'd rather prevent than treat, and you understand the difference

Check with us first if

• You're on warfarin, where the evidence about an interaction is genuinely conflicting.
• You take tacrolimus or another transplant medicine, where subtherapeutic levels have been reported.
• You're diabetic and considering juice, because of the sugar load.
• You're buying for someone in residential care, where the pooled result was null.
• You get infections often and haven't had them investigated.

• Whole cranberry fruit powder capsule. Best known for: The dried whole fruit, PACs plus everything else. Absorption: Studied around 500 mg a day in the whole-fruit trials. Typical use: A middle option between juice and a concentrated extract.
• High-PAC standardised extract. Best known for: Concentrated specifically for proanthocyanidins. Absorption: Studied around 240 mg a day in the standardised trials. Typical use: The form where you can actually check the active dose.
• Juice. Best known for: PACs plus a large volume of fluid, and the fluid matters too. Absorption: 500 mL a day of 27% juice was used over eight weeks. Typical use: Watch the sugar in sweetened versions.
• Capsule labelled by fresh-fruit equivalent. Best known for: The 25,000 mg to 70,000 mg packs that dominate Australian shelves. Absorption: The equivalent number says nothing about PAC content. Typical use: Look for a declared PAC figure instead.
• Cranberry with probiotics. Best known for: Adds Lactobacillus strains with their own urinary evidence. Absorption: Two actives rather than one. Typical use: Worth considering for recurrent problems.

Reference values. There's no Nutrient Reference Value for cranberry, because it's a fruit rather than a nutrient.

Typical supplemental range. Australian packs are usually once-daily capsules labelled 25,000 mg to 70,000 mg of fresh fruit equivalent. That number tells you about concentration ratios, not about active content. The figure that tracks trial benefit is proanthocyanidins, at 36 mg a day or more, and it's rarely declared. Trials used roughly 500 mg a day of whole fruit powder, 240 mg a day of a high-PAC extract, or 500 mL a day of 27% juice.

Upper level. None is set, and Schedule 1 records no dose cap for Vaccinium macrocarpon (item 5118) or Vaccinium oxycoccus (5121). The practical limit is oxalate load rather than a toxicity ceiling, which is why a kidney stone history changes the answer.

Worth knowing. If a pack doesn't declare proanthocyanidins, you can't compare it on the thing that matters. Your needs depend on your age, diet and health circumstances. Talk to one of our naturopaths.

Food first, where the diet allows it.

• Cranberry juice: trials used 500 mL a day of 27% juice
• Fresh or frozen cranberries: very tart; rarely eaten plain in Australia
• Dried sweetened cranberries: common in muesli and bars; sugar is usually added

This list is the part of the page we will not shorten. If any of it applies to you, talk to one of our naturopaths or your doctor before starting.

• History of calcium oxalate kidney stones. Cranberry increased 24-hour urinary oxalate excretion; avoid on that basis.
• Warfarin. The evidence is genuinely conflicting, with NCCIH describing it as such rather than settled either way.
• Tacrolimus and other transplant medicines. Concurrent use has resulted in subtherapeutic serum levels.
• Active urinary tract infection. Cranberry is a prevention product; an infection needs medical assessment.
• Institutionalised and residential care populations. The pooled result was null in this group.
• Diabetes and blood sugar management. Juice carries a real sugar load, particularly sweetened versions.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before starting.