Myths vs facts: Selen and weight loss

Selenium is an essential trace mineral critical for thyroid function and antioxidant defense. A common myth is that selenium supplements directly cause weight loss. In reality, selenium deficiency can impair thyroid hormone production, potentially slowing metabolism and promoting weight gain. However, in individuals with adequate selenium status, extra selenium does not lead to measurable weight loss. Clinical studies have not demonstrated that selenium supplementation increases resting metabolic rate or enhances fat loss in well-nourished populations. Moreover, high doses are toxic (selenosis), causing nausea, hair loss, and nerve damage. The evidence for a weight-loss effect is weak, mostly mechanistic or derived from deficiency states. For healthy individuals with a balanced diet, selenium supplementation for weight loss is not recommended. A calorie-controlled diet and regular physical activity remain the evidence-based approach.