Home Articles Overview of the Different Types of Thyroid Medications
Overview of the Different Types of Thyroid Medications
Tuesday, 14 July 2009 19:48

There are many different thyroid hormone medications on the market and a lot of controversy and confusion between them.  This article will outline a general overview of the various types and functions of each and how these medications are manufactured.  However, first it is important to know a little background information about the function of the thyroid and the hormones it produces for the body.  This will help in understanding the differences between the medications available.


What Hormones does the Thyroid Produce?


The thyroid produces T4 (thyroxine) and T3 (triiodothyronine).  These hormones will circulate throughout the body and influence virtually every cell in the body.


The thyroid gland is controlled by TSH which is a hormone released by the pituitary gland in the brain.  If the pituitary gland secrets more TSH this will signal the thyroid gland to produce more thyroid hormones. 


Thyroid patients are typically monitored by their TSH levels, free T4 and free T3 levels. This will give your doctor information on what medication and how much one should take.  Thyroid medication is tailored to the individual.  Everyone responds slightly different to thyroid medications.  Thus, it is often required to get lab work done every 4-6 months so one’s thyroid medication levels can be adjusted.


What is the Function of Thyroid Hormone in Body?


Thyroid hormone affects many systems in the body. It increases metabolic rate, body temperature, heart rate, and myocardial contractility.  The correct level thyroid hormones are essential for your body to feel good.


In general thyroid hormones control one’s metabolism.  It influences almost every cell in the body.  Without thyroid hormones in the body one would not survive. 


How is Thyroid Hormone Medication Produced and Manufactured?


Thyroid hormone is produce by one of two methods.  The first method is thyroid hormone can be manufactured using synthetic components.  This means that the medication is not natural but a synthetic hormone made in a laboratory.  Thyrolar, Cytomel, Unithroid, Leoxyl, Levothroid, and Synthroid are all synthetically manufactured thyroid hormones.


The second method for developing thyroid hormone is to extract the hormone from animals.  This is called natural or non-synthetic thyroid hormone.  Desiccated thyroid is derived from domesticated animals that are used for food by man (either beef or hog thyroid) and thyroglobulin is derived from thyroid glands of the hog.


In the media you will see arguments for synthetic vs natural hormone medications.  Many endocrinologist prefer the synthetic formulations of thyroid medications because historically the dosing in each pill tends to be more consistent. On the flip side many patients swear by the natural thyroid hormone medications working better and making them feel more normal.  This is a popular discussion that I will leave for a future article.



What is the difference between the different types of thyroid medications?


There are two types of thyroid hormones that the body must have in order to function normally.  These hormones are called T3 and T4.  Some thyroid medications provide only T4 or T3, while others use a combination of both.  Here is a summary of the different medications and hormone components.


Synthetic T4 only

Unithroid (Levothyroxine)
Levoxyl (Levothyroxine)
Levothroid (Levothyroxine)


Synthetic T3 only

Cytomel (liothyronine)


Synthetic T3 & T4 combination

Thyrolar (liotrix)


Natural T3 & T4 combination

Armour (thyroid)



An endocrinologist will determine what thyroid medication and how much one should take.  A doctor will do blood tests to measure one’s TSH, free T3 and T4 levels.  For thyroid cancer patients the doctors will often do suppression therapy with thyroid medication. 


The ultimate goal of your doctor is to prescribe enough thyroid hormone medication in order to get one’s hormone level in the normal range and to help a patient feel normal. This can be very challenging for some patients.  Often a combination of the above thyroid hormone medication is required to reach normal levels.  The endocrine system is very involved and complicated so going to a specialist (endocrinologist) is often required.


thyroid cancer calculator

dropbox image



   low iodine diet grocery list small

Download Free!

Low Iodine Diet

Grocery List