Answer
Oct 30, 2025 - 10:46 AM
ERFA Thyroid and Armour Thyroid are both natural desiccated thyroid medications made from porcine (pig) thyroid glands, and they contain similar active ingredients: T4 (thyroxine) and T3 (triiodothyronine). However, they are produced by different manufacturers (ERFA in Canada, Armour in the USA) and may have differences in inactive ingredients or fillers, which can affect the tolerability for some people.
