Hi,
I am thinking about adding more Levo to my treatment. I'm currently taking 75 / day. My last resulta are:
Ft4: 1,17 (0,7-1,7)
Ft3: 2,58 (2-4,2)
TSH: 1,5
Ferritin: 20 (i'm working on it).
Question: is it possible to become HYPER on t4 alone? Isn't t4 supposed to be inactive in our bodies?
Thanks!!
T4 is an inactive hormone and it has to convert to T3. T3 (liothyronine) being the active hormone and brain and heart have the most T3 receptor cells.
You would feel better if your T3 was higher.
A17,
Both hyper & hypo symptoms may be felt when thyroid hormones are inadequate. Your FT4 is 47% through range & FT3 just 26%.
What new symptoms are you experiencing?
Neuro symptoms are worsening. It feels like electric discharges, mostly at night. MRI is clean. I'm thinking it's because of My Thyroid and i'm trying to do my best before adding t3. I consider it the last shot.My main doubt is what happens if t4 goes above range with t3 within range. Is it possible to become HYPER? Isn't supposed to be inactive?
A17,
Oh, sorry to hear that.
T4 is known as the inactive hormone but as well as converting to T3 & RT3, other metabolites include T4S, T4G, Tetrac and a proportion lost through urine.
There is thought as we have T4 thyroid hormone receptors that the newly formed hormones may have some other important bodily functions and their behaviours are dependant upon our livers function and anothers levels, but once we medicate thyroid hormone replacement meds we are altering the natural metabolic systems anyway.
You are looking under-medicated and given your resistance to adding T3 you should try raising Levo dose to see if FT3 levels can increase enough to alleviate symptoms. Your results indicate room for a 25mcg Levo raise.
I try to function on quite low levels of thyroid hormone too because higher levels have made me quite ill. What I found has really helped meds work are liver supports.
i think at the moment you are probably worrying unnecessarily about 'what happens if fT4 goes over rage' because your fT4 is nowhere near the top on your current dose, so a small sensible increase of 25mcg /day is fairly unlikely to get you to the top, let alone go over range.
But to answer your question ...if T4 goes over range with fT3 in range, then from what i've seen in looking at lots of people's results on here.. some people will feel overmedicated and some wont ... and there's no way to know which group you would be in .
I have been overmedicated a couple of times (annoyingly, both times my fT3 was not done)
But, i have felt perfectly fine with very over range fT4 :
TSH 0.041 .. fT4 20.5 [7.9-14] .. 206% .. no sign whatsoever of overmedication symptoms.
and i have been overmedicated (with all the typical symptoms) with these much lower fT4 results :
TSH 0.018 ..... fT4 19.9 [8-18] 119%
Which leads me to think that it is not the fT4 level in itself that produces the symptoms of overmedication for me.
Shame i don't know what the fT3 levels were , but that's all i got .
However there are have been a few people on here who have reported symptoms that could be overmedication on Levo , who had high end FT4 (but fT3 in range) who i have suggested to try a slight reduction ... and when they reduced their levo slightly , their symptoms improved .
So that leads me to think that for some people, some of the time. if just fT4 is high or over range.. they do feel symptoms of overmedication, even though their fT3 was in range.
Logically , you would think that is not possible because it is only T3 that has a direct effect on our T3 receptors inside cells, T4 ought not to be able to 'do' anything until it's converted to T3 first .... but the deiodinase system has so many complexities, and we know it's just not possible to see everything that is going on by just looking at blood levels of T4 /T3 ...., tissue levels will remain a mystery unless we get a biopsy ..... so we also have to look to the symptoms being experienced by the individual to try and figure out the bigger picture.
if you do increase Levo and it goes over range , or you feel symptoms of overmedication ....then no harm done . just reduce again and follow other avenues like adding a little T3 instead .
Being pedantic about terminology here , and i'm sure you know ......but you can't actually become 'Hyperthyroid' by taking excess thyroid hormone .... you could become 'overmedicated' if your dose is too high for you , but you could easily fix that by reducing the dose.
To be Hyperthyroid, your thyroid would have to continuously producing too much T4 /T3 by itself .. and the only way to reduce the excess levels of hormone it was producing would be to take antithyroid drugs.
Great explanation! Thanks!!
GP reduced my levothyroxine dose
More and more meds..?
GP won't raise my Levothyroxine
Levothyroxine 
