Keep in mind that in my opinion the best way to treat a thyroid patient is to test and adjust FT3 and FT4 levels with whatever type of medication is required to alleviate symptoms, without being constrained by resultant TSH levels. Symptom relief should be all important. Frequently we hear that this requires that FT3 is adjusted into the upper part of its range and FT4 adjusted to at least the midpoint of its range.
Thanks for your input. My (fabulous) thyroid doctor has retired and I am needing to find someone new. I've had a couple of not-so-great ones in the past; they just threw some low-dose generic synthroid at me and I never felt good or lost the excess weight. With your information, I can better monitor what medications I need or should be taking.
French_Flamingo
A T4 med such as Synthroid works fine for many people as long as they convert T4 to T3 adequately. If your body converts T4 adequately, and there are no adverse reactions, I think that using only a T4 med is simpler all around. If, for whatever reason, your FT3 level is not adequately in balance with FT4, and you need to get your FT3 levels higher to alleviate hypo symptoms, then that's when adding a direct T3 source such as Cytomel, or one of the desiccated T4/T3 combo meds works better.