over 55 changing thyroid meds

[candyrod]

partial thyroidectomy 30 years ago,levothyroxine to manage to present.  Now TSH level changing every 6 weeks. new dose .125mg levo.. from .150mg.symptoms tired,, fragile skin, intolerant to heat- temperature much above 85 degrees, weight gain 10 lbs in 6mo. no life style change.  New MD ordering adrenal/cortical tests.  How safe is free T-3 to take and what are the side effects? ( original diagnosis of Hashimotos with benign nodules (post surgical)  I was very energetic and haven't had a weight problem, post menopausal of 4 years at 59.  Are all the extra lab tests necessary?

[gimel]

If your doctor is changing you meds based on TSH alone, that is doomed to failure. TSH is a pituitary hormone that is affected by many variables, including the time of day when blood is drawn for the test. Plus, TSH does not correlate very well at all with hypo symptoms.  Far better would be to test and adjust the levels of the actual, biologically active thyroid hormones FT3 and FT4, as required to alleviate symptoms.  Symptoms should be what it is all about.  FT3 correlates best with hypo symptoms.  

Regarding medication, I would suggest that decisions about any med change should wait until after testing for FT3 and FT4.  Many patients do quite well with a T4 only type med, if their body converts T4 to T3 adequately.  If the FT3 is too low and shows an imbalance with FT4, then a T3 med would be helpful in increasing the FT3 level.