Ask Larry:

Your Question: Which is best for helping control my thyroid function? Cytomel or Synthroid?

Larry’s Response: Liothyronine (T3, Cytomel) is superior to levothyroxine (T4, Synthroid) for controlling thyroid function.T4 is normally converted to the active T3 in the body. The conversion process often seems to be at the root of the problem. When T4 levels are normal and the person still feels poorly it is likely because he/she isn’t converting efficiently.

T4 itself also pushes TSH levels to normal, but often fails to make the person feel better.

Doctors who practice clinical medicine look at lab values as second in importance to how their patient feels. Many doctors, however, prefer to look only at the numbers and adjust orders from there.

Keep in mind, there are numerous substances and drugs that can interfere with thyroid function. The common culprits are drugs that inhibit absorption of minerals (those used to treat gastric reflux and heartburn), soy products, and inflammatory foods (wheat is particularly inflammatory), including sugars.

Finally, more is not always better. Regularly increasing doses can lead to more side effects without overall improvement.