Levothyroxine is a synthetically produced form of thyroxine, a major endogenous hormone secreted by the thyroid gland.[F4633] Also known as L-thyroxine or the brand name product Synthroid, levothyroxine is used primarily to treat hypothyroidism, a condition w…

Liotrix is a synthetically derived thyroid hormone replacement preparation. It consists of levothyroxine sodium (thyroxine, T4) and liothyronine sodium (triiodothyronine, T3) in a 4 to 1 ratio by weight. Liotrix was developed when it was believed that serum l…

Thyroid extract is dried and powdered thyroid glands from pigs containing tiiodothyronine (T3) and thyroxine (T4) used to supplement low or absent thyroid activity.[A190831,L11755] Thyroid extract has been described in literature to treat hypothyroidism since…