Boron is the chemical element of atomic number 5, a non-metallic solid, which is often sold as a bone health supplement which may have the potential to boost beard growth.

One study conducted in 2011 has suggested that Boron supplementation can increase Dihydrotestosterone (DHT) and free testosterone levels 1) When consumed in the appropriate quantities. It was shown over the study to also decrease the mean levels of estradiol, an estrogen. The dose given in the study was 10mg per day.

It achieved this raise in androgens, by inhibiting Sex Hormone Binding Globulin (SHBG). SHBG binds to free testosterone aiding in its aromatization into estradiol. Inhibiting SHBG allows Free Testosterone to be metabolised more readily into DHT (and other androgens) without being converted into estrogen, which bodes well for our beards.

However, it should be noted that the findings of the above study, are contradicted by an earlier study,2) conducted by the same researchers in 1997. The outcome of the earlier study indicated increased estrogen in addition to testosterone.

Generally speaking newer studies are often given precedence, given the more advanced techniques and methods as time progresses. It is noteworthy however, that the earlier study had a larger data set.

1)
Comparative effects of daily and weekly boron supplementation on plasma steroid hormones and proinflammatory cytokines.|http://www.ncbi.nlm.nih.gov/pubmed/21129941
2)
The effect of boron supplementation on its urinary excretion and selected cardiovascular risk factors in healthy male subjects.|https://www.ncbi.nlm.nih.gov/pubmed/9197924