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Limited evidenceVitamins & minerals

Boron Glycinate

A trace mineral in a chelated form, marketed for bones and hormones. The hormone claims trace back to one small metabolic-ward study in boron-depleted women; whether topping up boron helps anyone eating normal amounts of fruit and vegetables is unproven.

Evidence last reviewed: August 2026

What the science says

  • Effects on calcium and hormone levels Limited evidence

    In a metabolic unit study of 12 postmenopausal women first fed a low-boron diet for 119 days, 3 mg/day of boron reduced urinary calcium and magnesium loss and raised serum estradiol and testosterone. The effect was demonstrated against induced depletion, which is not the situation of a well-fed supplement buyer.

  • Bone health Limited evidence

    A narrative review of boron and bone concludes that boron influences mineral metabolism and bone development in animal and short human studies, but that the human evidence base is small and no trial has measured bone density or fracture outcomes over a meaningful period.

  • Testosterone and athletic performance Limited evidence

    A systematic review of mineral and trace element supplementation in exercise found no reliable performance or body-composition benefit from boron in athletes. The chelated glycinate form has not been shown to work differently from other boron salts.

Dosage & safety

Studied dose3 mg/day is the amount used in the classic study and the usual supplement dose. Typical dietary intake from fruit, vegetables, nuts and legumes is roughly 1–2 mg/day.
SafetyThe tolerable upper intake level for adults is 20 mg/day; higher intakes cause nausea, vomiting and diarrhoea, and boric acid is toxic in overdose. Because boron raises circulating estradiol and testosterone in depletion studies, avoid it in hormone-sensitive conditions and if you take hormone therapy without discussing it first. Avoid in pregnancy, breastfeeding and kidney impairment, since boron is cleared by the kidneys.

Scientific references

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