Levothyroxine, sold under brand names like Unithroid & Synthroid, treats this gland when it's underactive
[DOC] [TLE] Synthroid (levothyroxine sodium tablets, USP) | Official Website [PAR] Learn about Synthroid (levothyroxine sodium tablets, USP) and click for full safety 
... is used to treat a condition called hypothyroidism, except in cases of temporary 
... is usually associated with an inflammation of the thyroid gland (thyroiditis).