SeMet contains selenomethionine, a natural form of the mineral selenium that is the prominent form which the body absorbs from food sources. It is the main form of selenium that is stored in the body, is more effectively used than other forms and is absorbed 1.5-2 times better than selenite, a form commonly found in supplements.

Selenium levels of plant-based foods are unpredictable as they will vary with soil selenium content, making it important to supplement with the absorbable and efficient form of selenium to obtain its health benefits. Selenium is necessary for immune function, supporting the production of glutathione, a powerful antioxidant, and boosting immune cell activity. Supplementing with selenium is important for those who want to promote a healthy immune system and normal cell growth especially as selenium soil content is depleted in many areas of North America.