Our member, Ella, has analyzed her own T4 plus T3 thyroid replacement needs and offers a terrific explanation of how she arrived at her conclusions. Follow her thinking in her message to metabolism.com
Dear Dr. Pepper: I’m a 54 year old female, three years out from a total thyroidectomy for papillary (w/follicular variant) microcarcinoma. I-131 was not done. Followup testing results show NED. Replacement therapy began with Synthroid 150mcg 3.5 weeks post surgery and I was unwell for 6 months following. TSH was 1.4 which is too high for me. I requested a change to 175mcg and have been there since…doing reasonably well. But I know I could feel better. When I was taking Cytomel for 3 weeks post surgery I felt better than I ever felt in my adult life. Synthroid has been okay, but not quite where I think I could be. Endocrinologist has historically resisted testing for FT levels. I ordered labs myself since I am currently uninsured (long story short: COBRA expired, PCIP stopped taking applications 13 days before I would qualifyâ€¦so I have to wait until January 2014). Latest labs as follows: Tg <0.5 (range 0.5-55.0) TgAb <20 (range 0-40) TSH 0.068 (range 0.450-4.500) FT4
1.74 (range 0.82-1.77) FT3 3.0 (range 2.0-4.4) TSH is low but acceptable. I need to be between 0.4 and 0.04 according to my endocrinologist. I am experiencing no hyperthyroid symptoms. FT4 is at 96% of the range and FT3 is at 42% which is more or less consistent with LT4 monotherapy from what I have read. I presented this to my endocrinologist. I explained that I understood that since the thyroid gland produces all of the body’s T4 and about 20% of the body’s T3, the rest of the T3 is converted largely by the liver and kidneys from the available T4 as needed. For people whose thyroids work perfectly, this is great. For thyroidectomized people on LT4 monotherapy like me, the FT3 levels can obviously never be adequate through conversion alone. While there is no exact formula that can replicate the human body’s production of the ideal proportions of thyroid hormones, a combination of LT4 and LT3 is more natural than relying on T3 conversion from LT4 intake alone. Ideally, FT4 and FT3 levels should be 60-80% of the range. I would like to see my FT3 at between 3.5-3.8 and I think it would make a difference in how I feel. That said, I proposed a reduction of my Synthroid to 150mcg with an addition of Cytomel at 10mcg for a trial period to see if this improved my FT3 level, and potentially help me feel better. I would run labs again in 3 months. He refused to even allow me to try saying that LT4 therapy is the only therapy that is acceptable. This doctor is on the thyroid cancer endocrinology team at a fine, progressive, cancer center in Miami, FL where I had my surgery and followup testing. My surgeon is the CMO of the center and is the finest doctor I have ever known. I love everything about the centerâ€¦except my endocrinologist who I have had a couple of issues with before. I considered asking for someone else in the department, but am not sure that would help me. At this point I am considering finding a new endocrinologist, though that is a daunting prospect. I am concerned that it might be a frying-pan: fire situation. Can you recommend any physicians in the Broward, Palm Beach, Miami-Dade area who are more accepting of patient input and who would be open to LT4/LT3 combination therapy? I’m at a lossâ€¦ Any help you can provide would be appreciated. E.