Hypothyroidism Support Group
Hypothyroidism is the disease state caused by insufficient production of thyrohormone by the thyroid gland. There are several distinct causes for chronic hypothyroidism, the most common being Hashimoto's thyroiditis and hypothyroidism following radioiodine therapy for hyperthyroidism. Advanced hypothyroidism may cause severe complications, the most serious one of which is...
I have what may be a dumb question about Free T4. If you are receiving medication to elevate your Free T3 to within the optimal range, what does it matter what your Free T4 level is?
I have read that Free T4 is inactive/ "storage" hormone waiting to be converted to Free T3 (active hormone) if needed. So, if medication raises your Free T3 sufficiently, why is Free T4 level important?
I ask because apparently, my thryroid produces very little Free T4. Since I have to supplement to get Free T3 into my system, do I still need shoot for Free T4 in the middle of the range?
I don't get it. Thanks.
I have read that Free T4 is inactive/ "storage" hormone waiting to be converted to Free T3 (active hormone) if needed. So, if medication raises your Free T3 sufficiently, why is Free T4 level important?
I ask because apparently, my thryroid produces very little Free T4. Since I have to supplement to get Free T3 into my system, do I still need shoot for Free T4 in the middle of the range?
I don't get it. Thanks.
Total T4 is BOUND thyroid hormone - bound to proteins to be exact. It acts as a "reservoir" for your Free T4 needs.
Free T4 is unbound thyroid hormone (ready for use by the body and easily converted by the body (mostly by the liver) to Free T3).
To feel "well" you really need both, and here's why:
Free T4 is used by cells and converted in times of need (expendable energy, hormonal fluctuations, and countless other reasons).
T4 only meds take about four weeks to get into your system fully and have a relatively long half-life.
Free T3 is immediately used, but can be depleted quickly (the half life of Free T3 is about an hour NOT to be confused with the T3 only med who's half-life is about six hours). Meaning, you can have alot of it, but it's gonna burn off quickly....and even quicker in "times of need" referenced above.
Too feel well, most people need a Free T4 of around 60-100% of range and a Free T3 over 50% of the range. There are some exceptions, but we're talking the majority of people.
More on that:
http://www.thyroid.org/wp-content/uploads/patients/brochures/FunctionTests_brochure.pdf
http://hypothyroidmom.com/the-thyroid-worlds-queen-t3/
I went to my doctor yesterday. I was very excited 2 months ago to find a doctor who agreed with the optimal targets that we talk about and who wanted me to try Nature Throid instead of Levothyroxine.
Howver, I didn't feel much better after making the switch and my labs confirmed that there wasn't much progress over the last 6 weeks.
November 2015
Free T3 was 38% of range
Free T4 was 16% of range
Vitamin D was insufficient (below range)
Labs from last week:
Free T3 is still 38% of range
Free T4 went down to below range
Vitamin D doubled and is in the normal range now (that's the good news)
Yesterday, the doctor nearly doubled by dose of Nature Throid. So maybe things will be better after another 6 weeks.
You are so right about needing a lot of PATIENCE with this!
I take slow-release cytomel and fell a lot better - but I am still experiencing exercise intolerance.
Now, thanks to Butterfly, I understand why I may very well need an increase in my synthroid.
I am saving up in my HSA to go to the doctor some time in March or April so I can pay for the minimum $700 that the lab work will cost. I expect I will find I can use an increase in all my medication.
Once again - thanks so much for this post!
T3 only therapy is potentially dangerous. T4 is less potent and takes a lot longer to exit the system.
However there are cases when special treatment is required. Fairly rare but in cases like mine where RT3 is off the charts, it binds to the cells blocking T4 or T3 (dont quote me Im not a Dr). The supposed theory there is, you can have perfect blood results and still feel hypothyroid. But there are also many other reasons you can feel unwell with a functioning thyroid.
Also keep in mind Hashimotos is not a thyroid disease, its an Auto Immune disease that effects the thyroid. So the first step is get the blood levels looking good (which is like applying a bandaid), then work on the other causes ie auto immunity.
I suggest reading Dr Ks book, why do i still have symptoms when.... (forget the title but you will find it). Wealth of knowledge.
In saying all this, T3 is definitely the more active (2.5x i think) hormone and obviously gets converted down the chain. In my case trying to get a 50% FT4 was adding fuel to the fire of an RT3 problem.
There is also a letter written by a paractitioner of NDT therapy who says FT4 (~20% of range) will be low and FT3 high (~80-90%).
It was a letter written to take to your Dr if you were trying to use NDT instead o synthetic T4. I cannot find it.
Nevertheless, get a good a holistic Dr and go from there. It took me 8 years of feeling unwell, and 2 years of putting off the RT3 test as its not done in my country and is expensive as its sent overseas. I wish I had done it 8 years ago. My opinion, and this is not advise or medical knowledge, but my opinion is they should consider RT3 in Hashimotos blood panels just the same as antibodies.
But RT3 is still controversial and a lot of mainstream medical people do not believe in it causing problems, Ill let other people decide for themselves.
But for me perfect blood work did not bandaid my thyroid problem, not did auto immune diet (although it has dropped anti bodies from like 4000 to 130, with anything below 60 being in remission).
Again, not medical advise above, just my thoughts and experience.