Selenium is an essential trace mineral that plays a critical role in various physiological processes, including antioxidant defense and thyroid hormone metabolism. Its relevance to testosterone and male reproductive health has been the subject of several scientific studies, although the evidence is moderate rather than robust.

Some research indicates that selenium supplementation may positively influence testosterone levels, particularly in men with low selenium status or infertility issues. Selenium is a cofactor for glutathione peroxidase, an enzyme that protects cells—including those in the testes—from oxidative damage. Excessive oxidative stress in the testes can impair testosterone synthesis. A few clinical trials have reported that selenium, sometimes in combination with other antioxidants like vitamin E or zinc, can increase testosterone levels and improve sperm parameters in infertile men.

However, results are inconsistent, and selenium supplementation does not appear to significantly increase testosterone in healthy men with normal selenium status. Major reviews and meta-analyses suggest only a modest benefit, primarily in populations with selenium deficiency or reproductive health concerns. There is currently no strong evidence to support selenium supplementation for testosterone support in the general population, but it may play a supportive role for specific subgroups.