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What are the risks of staying on T3 therapy for a long time?

What are the risks of staying on T3 therapy for a long time?

There was a boy who was born with congenital hypothyroidism and was raised on traditional T3 (Cytomel). He was never treated with a T4-containing medicine, and so essentially never had a molecule of T4 in his body. By age 26 he had developed normally with no problems. This underscores the fact that the importance of T4 lies very much in that it is “T3 waiting to happen.” Nevertheless, duration of treatment may be limited by risks of longer-term treatment (> one year or so). The potential of increased osteoporosis should be considered (especially in patients at risk). The studies that link increased osteoporosis with long-term thyroid therapy have been done with thyroid therapy managed much differently than discussed here. The studies involve patients managed with suppressive doses of T4-containing medicine, without regard to their body temperature patterns or clinical well-being. This manual should make it clear that many of these patients are perhaps being “pushed too far in the wrong direction with the wrong medicine.” I would not be at all surprised if the vast majority of the patients involved were clinically hypothyroid with low body temperature patterns. Perhaps if they were caused to be clinically euthyroid with normal body temperature patterns, they would enjoy increased bone densities. T3 therapy usually lasts on the order of months, and the osteoporosis studies involved patients treated for years (e.g., 10 years). I am not concerned about increased osteoporosis in patients who are treated for months. Circumstances have been such that I have treated a few patients for more than a year, and some for a couple of years. I have done serial bone scans in a couple of these patients who I felt were at higher risk for osteoporosis. I was able to see no decreased bone density in this tiny cohort, and I wondered if it might have actually increased. But since osteoporosis is a serious condition, the potential should be seriously considered and weighed and managed accordingly.