Certain drugs can interact with your thyroid hormone to negatively affect your thyroid function. These are just a few commonly used medications that can affect your thyroid:
Amiodarone
Aspirin (more than 3,000 milligrams daily)
Estrogen (for example, in hormone replacement therapy, or in the oral contraceptive pill)
Iron tablets
Iodine
Lithium
Propranolol
Corticosteroids
