how many mg is in a grain
According to the conversion chart, 1 grain (60 mg) is equal to 100 mcg snythroid, and 90 mg Armour is equal to 150 mcg levo. According to the manufacturer, there is 38 mcg of T4 and 9 mcg T3 in each grain. So if you work it out that way, 90 mg has only 57 mcg of T4 and 13.5 mcg T3.