What role does Selen play in weight loss?

Selenium is an essential trace mineral that functions primarily through selenoproteins (e.g., glutathione peroxidases, thioredoxin reductases) involved in antioxidant defense and thyroid hormone metabolism. Some observational studies have reported an inverse association between selenium status and body fat, suggesting a potential role in energy metabolism. However, the evidence for a direct weight-loss effect is weak and inconsistent. Randomized controlled trials are scarce, and selenium supplementation in replete individuals does not promote weight loss. Moreover, excessive intake (above the tolerable upper intake level of 300 µg/day) can cause selenosis, characterized by hair loss, nail brittleness, and neurological symptoms. The idea that selenium alone or in combination with other nutrients significantly reduces body weight is not supported by robust scientific data. In the context of a MyBody-X test, a low selenium level may indicate a deficiency that should be corrected for general health—especially thyroid function and antioxidant capacity—but not as a weight-loss strategy. Supplementation should only be considered under medical supervision and after confirmed deficiency.