Cytomel is the commonly associated brand name for the synthetic thyroid hormone Liothyronine Sodium. This is a perfect replica of the naturally produced thyroid hormone triiodothyronine, or what is commonly referred to as the T3 hormone. While synthetic Cytomel has been available since the 1950’s, thyroid hormones including T3 have been used medicinally since the 1890’s. Early thyroid treatment plans were simply pure animal extracts and contained pure forms of the T3 and T4 hormone. Extracted thyroid hormones proved very useful in therapeutic treatment plans, specifically in the treatment of hypothyroidism. This is a condition in which the thyroid simply no longer produces enough thyroid hormones, which can lead to weight gain, loss of energy, hair loss and changes in the appearance and texture of the skin. With the introduction of Cytomel, the synthetic model of the T3 hormone, this has provided a much safer and sanitary hormone for such treatments.