Abstract: A stable dosage form of levothyroxine sodium which includes a stable complex of levothyroxine sodium and a cellulose compound, polyvinylpyrrolidone or a Poloxamer, which complex is adsorbed on the surface of a cellulose compound carrier. In a first embodiment the stable complex of levothyroxine sodium is prepared by mixing the levothyroxine sodium with a complexing agent such as polyvinylpyrrolidone or a Poloxamer, dissolving the resulting mixture in a polar organic solvent such as water, methanol, ethanol, propanol, isopropyl alcohol, methylene dichloride or butanol, adding a cellulose carrier to the liquid and subsequently drying the resulting mixture to obtain a powdery, stabilized complex of levothyroxine sodium and polyvinylpyrrolidone or Poloxamer adsorbed on the cellulose carrier. In a second embodiment the levothyroxine sodium is at least partially dissolved directly in the polar organic solvent and a cellulose carrier is added to the solution to produce the stabilized levothyroxine sodium complex.