First major question:
Do or did you take your Thyroid medication prior to the blood draw for the lab work?
If so your FT3 levels will be artificially high reading and not representative of what is going on. BOTh of your meds you were on have a large percentage of T3 in it. And the T3 levels peak about 2 to 4 hours after taking it.
Do you split your dose of both the Nature THyroid and the Cytomel? If not you are putting yourself and your body on one hell of a roller coaster ride. As noted above, T3 peaks about 2 hours after taking it and then wears off over the next several hours. if you take it all in the morning you as slamming your body with a HUGE dose of T3, which can cause many people to go Hyper for a short time. Then as the T3 is used up, you crash by the end of the day. And the next day you repeat the roller coaster ride. By splitting the dose to at least 2 doeses if not three during the day can help even out the T3 levels.
This roller coaster ride could also contribute to the RT3 levels being high. As the pituitary takes usually its daily analysis of thyroid levels in the morning. At which point you may have literally shotgun blasted the pituitary and the pituitary says HOLY COW, there is a tremendous amount of T3 here. WAAAAAY too much, I will instruct the body to convert any T4 into RT3 to stop this madness!
With all of this, I think that switching and adding T4 is a big mistake!
Reverse T3 is ONLY made from the conversion of T4. That is the ONLY way that RT3 can exist. T4 can only be converted into two primary things. Free T3, OR, Reverse T3.
If you are worried about high levels of RT3, then the LAST thing you would even consider doing is adding T4 which is the source for RT3 manufacture.
Your body I think is sensing the too high of FT3 and thus telling your body to convert to RT3 so as to regulate what it believes is a too high of FT3 level. So the FT4 levels may be so low because your body is working over time and using every bit of FT4 to be converted into RT3 to stop the overabundance of FT3.
I personally think a better approach should be to reduce your Cytomel dosage. 35 mcg of T3 in Cytomel plus Nature Thyroid which is also high in T3 is a large dose.
I think the key is to keep the FT4 levels low so as to prevent the conversion of the T4 into RT3. Also to lower the FT3 levels so the body stops thinking it needs to regulate up the RT3 levels.
Usually you want to only make one change at a time. And if my hypothesis is correct that your body is sensing too high (and you are showing above the top of the range) FT3, the reduction of Cytomel should give a very immediate lowering of the FT3 levels. Which MAY then slow the rate of conversion of FT4 into RT3.
Since Cytomel and T3 are quick acting. I think a new blood test a couple weeks after the reduction should show a drop in FT3 levels. The FT4 levels will take much longer (6 weeks or so) to show a change. If my hypothesis is correct, I think as the FT3 levels come down, your FT4 levels may rise because you will still be getting plenty of T3 and there will be less pressure to convert the T4 into RT3. As the RT3 clears out, then the FT3 can start to do the job at the cell receptors as they will be open to accept the FT3 rather than plugged up or competing for receptors with RT3. And hopefully you will begin to feel better.
You may have to drop the cytomel more than once in smaller increments. I would shoot for the goal of getting the FT3 level to about 67% of the range where you are over the top right now. Then see what happens to the FT4 and RT3 levels.
you may find that you in fact need to drop your Nature thyroid dosage as well if the RT3 doesn't clear up. The nature thyroid (Besides your thyroid gland production if it is producing anything) is the only source of T4. And thus reducing it AFTER you get your FT3 levels to about 67% of the range to cut off supply of T4 to convert may be necessary.
This is like I said above only a hypothesis of mine. Others may have a different idea. But you asked for opinions and I gave you one :) Take it for what it's worth!
Thanks for taking the time to comment. The labs were drawn with my usual trough.
I'm actually not changing multiple things, I've been on my current combination for 5 months now. My RT3 is low at the moment, please see my lab results from last week in my initial post. Even though my RT3 has cleared since April, my FT4 refuses to go up My Dr wants my T4 and RT3 at least in range and it's not moving even though I'm taking 2 grains of Naturethroid a day. I take my Cytomel in 3 doses - 20mcg loading dose in the am, 10mcg at 1pm and 5mcg at 6pm.
Naturethroid is not able to raise my FT4 so we are trying tirosint. I have no problems lowering the Cytomel if needed.
What happened with the tirosint? I'm in the same boat and I'm so sick!
You have attached your post to a very old thread, and it is doubtful you will get an answer. If you will tell us about your situation, your symptoms, and your test results and reference ranges shown on the lab report, we will be happy to try and provide some useful analysis and recommendations..