selenium

Selenium is an essential trace element and mineral required in small amounts for human health. It is not synthesized by the body and must be obtained from dietary sources such as Brazil nuts, seafoods, meats, grains and dairy products. Medically and nutritionally classified as a mineral supplement or trace element therapy rather than a pharmaceutical drug per se. Selenium acts primarily as a cofactor for selenoproteins including glutathione peroxidase (an antioxidant enzyme that protects cells from oxidative damage), iodothyronine deiodinases (enzymes involved in thyroid hormone metabolism), and thioredoxin reductase (important for DNA synthesis). Its main mechanism of action is through its role in antioxidant defense systems—neutralizing reactive oxygen species—and supporting immune function. Clinically it is used to treat or prevent selenium deficiency; it has also been studied or used off-label for conditions such as Hashimoto's thyroiditis and high cholesterol. Excessive intake can lead to toxicity with symptoms like hair loss and neurological effects. It is available over-the-counter in oral forms (tablets/capsules) or intravenously when oral administration isn't possible.

Brand names

Selenium TRSelepenSele-PakAqueous SeleniumOceanic SeleniumNicomide

Other names

SelenSelenioSéléniumSelenium elementalSelenium metallicum