Boron influences the metabolism of calcium, magnesium, phosphorus, and vitamin D. It inhibits the hydroxylase enzymes that deactivate 17β-estradiol and vitamin D, effectively extending their half-lives. Boron also reduces SHBG (sex hormone-binding globulin), which increases free testosterone — though the magnitude is modest.
Dietary boron comes from fruits, vegetables, nuts, and legumes. Average dietary intake is 1-3mg/day. The proposed adequate intake is 1-13mg/day depending on the source.
Boron may increase estradiol levels; additive estrogenic effects
Not Prohibited
Naghii MR et al. Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines.
Nielsen FH. Studies on the relationship between boron and magnesium.
Penland JG. Dietary boron, brain function, and cognitive performance.
Independently graded against 173,636 indexed supplements with 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, and NIH DSLD | Last updated: April 2026
Not medical advice. Based on published clinical research and systematic reviews.