An underactive thyroid gland is a very common condition. In fact, levothyroxine, the hormone generally used to treat hypothyroidism, is the most commonly prescribed drug in the US. After a period of dose adjustment, many people do quite well on this medication. But others do not feel good despite rigorous treatment. Natural desiccated thyroid such as Armour Thyroid from pigs contains more than one kind of thyroid hormone. Would you feel better on Armour Thyroid than on levothyroxine?
Would You Feel Better on Armour?
Q. About two decades ago, I was diagnosed with hypothyroidism. I took levothyroxine (Synthroid) for a few years and then was switched to Armour Thyroid. My wife was also taking Armour and we both thought we felt better on it.
Then we couldn’t get Armour for many months and had to go back to Synthroid. When Armour once again became available, we happily went back to it.
I told my endocrinologist about this back-and-forth switch, with both my wife and I preferring Armour to Synthroid. He said that most of his patients tell him they feel better on Armour. What’s the difference?
What Is the Difference Between Synthroid and Armour?
A. Levothyroxine (Levoxyl, Synthroid) is a synthetic hormone that only contains T4 thyroid hormone. The body has to change T4 to the active form, T3. To do that, an enzyme knocks one iodine atom off the molecule. Some people have a harder time with this conversion, presumably because their genes encode a less active enzyme.
Armour thyroid is a natural product derived from dried animal glands. (Other brands include Nature-throid and Westhroid). Desiccated thyroid gland contains both T3 and T4, which may explain why some people prefer this formulation. The ratio of T3 to T4 in Armour is not the same as the ratio produced by a healthy human thyroid gland, however. Consequently, doctors are sometimes reluctant to prescribe it.
Does Armour Cause Problems for Older People?
Q. I’ve read your articles on Armour Thyroid and asked my doctor to change my Synthroid prescription to Armour. He responded that he doesn’t like to prescribe Armour Thyroid to patients over 65. Why do you suppose that is?
A. We don’t know for sure, but we suspect some doctors worry about cardiovascular complications (Vnitrni Lekarstvi, Winter 2018). Excess thyroid hormone could cause heart palpitations or arrhythmias. Although it is not clear that desiccated thyroid extract results in higher doses of T4 or T3, physicians may fear that they can’t control the dose properly.
What Do Thyroid Patients Say?
This concern might be primarily theoretical, however. A study of hypothyroid patients taking synthetic levothyroxine (Synthroid or others), combination levothyroxine and triiodothyronine (T4 and T3) or desiccated thyroid extract (Armour) found no additional cardiovascular risk from combination or natural therapy (Southern Medical Journal, June 2018).
You are not the only one to report benefit on desiccated thyroid extract. To learn more about the differences between various thyroid formulations and why they matter, you may wish to read our eGuide to Thyroid Hormones. It is an in-depth online resource.