I'm wondering what effect do antacids have on thyroid hormone pills?

Antacids interfere. with thyroid hormone absorption. Thyroid should be taken on an empty stomach. Also avoid taking iron, calcium, or vitamins at the same time as thyroid.
Can alter absorption. Don't take antacids with thyroid replacement pills. Thyroid replacement w/brand name T4 is best taken in the am an hour before you eat your first meal. Don't take w/iron, calcium or vitamins either.