The dosage of Armour Thyroid is determined by the condition being treated and is individualized according to patient response and laboratory findings. Armour Thyroid may interact with birth control pills or hormone replacement therapy, blood thinners, insulin or oral diabetes medication, medications that contain iodine, salicylates such as aspirin and others, or steroids. Tell your doctor all medications you use. Current information shows Armour Thyroid may be used during pregnancy. Tell your doctor if you are pregnant because your dose may need to be adjusted. Thyroid hormone passes into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.