Euthyrox 100 mcg Tablets are a thyroid hormone replacement medication used to treat hypothyroidism. These tablets contain levothyroxine sodium, a synthetic form of the thyroid hormone thyroxine. Levothyroxine works by replacing the hormone that is normally produced by the thyroid gland to regulate the body's energy and metabolism. It is essential for normal growth, development, and overall metabolic functions. Euthyrox tablets help restore adequate hormone levels and alleviate symptoms of an underactive thyroid, such as fatigue, weight gain, and cold sensitivity.