Low free T4 - below normal free T3

[ukap]

A blood test last week shows FT3 below normal 2.1 (range 2.3-4.2) in March it was 3.5 - my highest ever. Total and free T3 is usually is on the low end except for March.

Free T4 is 0.9 (range 0.8-1.8) in March it was 1.4 the highest ever. Free & total T4 has always been on the low end

Iron 50 (45-160) and ferritin 64 (10-232) is low - but have always been on the low side. I take supps but I guess from the blood test I obviously need more.

Since March I had tried to lower my dosage slightly from daily 100 lev + 1 NDT grain to daily 50 lev + 1 NDT grain. I didn't want to over medicate & thought I would see how I fared with a lower dose. The 1 grain NDT plus 50 levothyroxine seemed like a reasonable amount to me (female 125 lbs).

My results last week alarmed me as this is the first time my Free T3 not just low but BELOW range. I could tell something was off because I have noticed no energy, sandpaper hands and straw hair in just the last month.

My question is - what caused the Free T3 to drop below normal even when on what appeared to be a reasonable dosage of medication?

How do I increase this amount slowly - days - weeks - months?

[humanbean]

I don't understand why you reduced your thyroid medication from 100mcg Levo + 1 grain NDT down to 50mcg Levo + 1 grain NDT.

What were your results and reference ranges just before you decided to lower your dose?

Another comment... Reducing Levo by 50mcg per day in one big jump is far too quick. And it isn't a "slight" reduction, it's a massive reduction.

A blood test last week shows FT3 below normal 2.1 (range 2.3-4.2) in March it was 3.5 - my highest ever. Total and free T3 is usually is on the low end except for March.

You say that the highest your Free T3 has ever been is 3.5 (2.3 - 4.2). This is 63% of the way through the range, which is not bad but many people don't feel well until their Free T3 is 70% of the way through the range or over. Some people only feel well with their level slightly over the range. Free T3 being 63% of the way through the range definitely wasn't a justification for halving your dose of Levo.

Taking NDT alone will usually reduce TSH and Free T4, and raise Free T3. By adding in Levo I'm not sure what the effect would be.

[ukap in reply to humanbean]

Thank you for replying - appreciate your feedback. TBH I get nervous about taking medication & wanted to take the lowest dose possible. Obviously I got that wrong and now need to fix this.

[greygoose in reply to ukap]

Stop thinking of it as medication. You are taking thyroid hormone replacement, without which - and enough! - you can't live. You're not taking drugs. And, even if you did over-dose a little, it wouldn't do you any harm. It's silly to try and get by the with the lowest possible dose because it doesn't serve any useful purpose - it just makes you ill, as you've found out!

My question is - what caused the Free T3 to drop below normal even when on what appeared to be a reasonable dosage of medication?

Well, it obviously wasn't a reasonable dosage, was it. On what did you base that opinion? Why would you think that 50 mcg T4 + 1 grain NDT - a total of 118 mcg T4 and 9 mcg T3 - was reasonable? It's quite a small dose. And, it doesn't matter how much you weigh, that has very little to do with it. You need what you need, and you especially need more T3, because that's the active hormone, needed by every single cell in your body.

So, what caused your FT3 to drop below normal was that you were only taking a small amount of T3, and you reduced the amount you had available to conversion. And that is what happens when you do that.

My personal opinion is that you needed an increase, not a reduction in dose.