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Limited evidenceJoints & skin

Calcium Fructoborate

A plant-style boron-carbohydrate complex studied mainly for knee discomfort. Two small trials from the ingredient's developers reported symptom relief; nobody has independently replicated them.

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What the science says

  • Knee discomfort Limited evidence

    A double-blind, placebo-controlled study in subjects with knee discomfort found that 110 mg twice daily reduced WOMAC and McGill pain scores by day 14, with no change in the placebo group. The study was short, small, and conducted by the ingredient manufacturer.

  • Inflammatory markers Limited evidence

    A double-blind placebo-controlled pilot study in middle-aged people with primary osteoarthritis reported reductions in CRP and some lipid markers. It was explicitly a pilot with a small sample, and the biomarker changes were not linked to clinical outcomes.

  • Compared with established joint supplements Limited evidence

    Calcium fructoborate has not been tested head-to-head against glucosamine, chondroitin or NSAIDs in any published trial. All the human evidence traces back to two related research groups.

Dosage & safety

Studied dose110 mg twice daily (about 3 mg elemental boron per day) is the dose used in the published trials.
SafetyWell tolerated at studied doses. Boron intake above roughly 20 mg/day in adults is considered the upper limit and higher intakes can cause nausea and, in animal studies, reproductive toxicity. Avoid during pregnancy, and avoid in people with hormone-sensitive conditions, since boron can modestly raise sex hormone levels.

How to take it

TimingSplit into a morning and an evening dose, as in the trials.
With food?Take it with meals; it is well tolerated but food avoids any stomach discomfort.
Worth knowingCount the boron: at 3 mg/day this sits far below the 20 mg upper limit, but a separate boron supplement on top of it does not.

Frequently asked questions

Does calcium fructoborate help joint pain?

Calcium fructoborate has limited evidence for knee discomfort: a small, short placebo-controlled trial by the ingredient manufacturer found 110 mg twice daily reduced pain scores by day 14. No one has independently replicated it.

How much calcium fructoborate should I take?

Published trials used 110 mg of calcium fructoborate twice daily, morning and evening with meals, supplying about 3 mg of elemental boron per day.

Is calcium fructoborate safe?

Calcium fructoborate was well tolerated at studied doses, and 3 mg/day of boron sits far below the roughly 20 mg/day upper limit, but adding a separate boron supplement may not. Avoid calcium fructoborate in pregnancy and hormone-sensitive conditions, since boron can modestly raise sex hormones.

Is calcium fructoborate better than glucosamine?

Calcium fructoborate has never been tested head-to-head against glucosamine, chondroitin or NSAIDs, and all its human evidence traces back to two related research groups. There is no evidence it is better.

Scientific references

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