Levothyroxine is a synthetic form of the thyroid hormone thyroxine (T4), used to treat conditions like hypothyroidism, where the body does not produce enough thyroid hormone. It helps regulate metabolism, energy levels, and overall growth and development. Patients typically take levothyroxine as a daily oral medication. The dosage is tailored to individual needs, and regular blood tests are necessary to monitor thyroid hormone levels. Proper management with levothyroxine can help alleviate symptoms such as fatigue, weight gain, and sensitivity to cold.