hi Donna, i have been on synthroid for 6 yrs.,I also need to take supplemental iron because I suffer fron chronic anemia.the two drugs need to be taken seperatley because the iron interferes with your body's absorption of the synthroid.I am not familiar with armour (is it availible only in the states as i am from canada) so I dont know if it would affect absorption in the same way but definitley check with your doctor.kristen.