Armour Thyroid Conversion Chart. Armour® thyroid (thyroid tablets, usp)* for oral use is a natural preparation derived from porcine thyroid glands and has a strong, characteristic odor. Armour thyroid ½ gr t4 = 19 mcg t3 = 4.5 mcg t4 = 16.8 mcg t3 = 5.1 mcg physiologic thyroid activity 37.2 mcg sr caps armour thyroid 1 gr t4 = 38 mcg t3 =9 mcg t4 = 33.3 mcg t3 =10.1 mcg physiologic thyroid activity 73.7 mcg sr caps armour thyroid 1 ½ gr t4 = 57 mcg t3 = 13.5 mcg t4 = 50.2 mcg t3 = 15.2 mcg physiologic thyroid activity 111.

(t3 liothyronine is approximately four times as potent as t4 levothyroxine on a microgram for microgram basis.) they provide 38 mcg levothyroxine (t4) and 9 mcg. Armour thyroid ½ gr t4 = 19 mcg t3 = 4.5 mcg t4 = 16.8 mcg t3 = 5.1 mcg physiologic thyroid activity 37.2 mcg sr caps armour thyroid 1 gr t4 = 38 mcg t3 =9 mcg t4 = 33.3 mcg t3 =10.1 mcg physiologic thyroid activity 73.7 mcg sr caps armour thyroid 1 ½ gr t4 = 57 mcg t3 = 13.5 mcg t4 = 50.2 mcg t3 = 15.2 mcg physiologic thyroid activity 111. Armour® thyroid (thyroid tablets, usp)* for oral use is a natural preparation derived from porcine thyroid glands and has a strong, characteristic odor.