This might sound like a stupid question but does Levothyroxine increase T3 or does it just increase T4 (and of course lowers TSH)?
The reason I ask is that I have now been taking Liothyronine 5mcg once a day for over two weeks and I feel worse than just on Levothyroxine. If I increase to 7.5mcg or 10mcg I feel awful. I am meant to be on 10mcg as prescribed by endocrinologist on 17th July but I asked if I could initially halve the dose as my body adjusts.
I received her clinic letter following appointment (17th July) which included the latest blood test results from bloods taken on that day before I started the Liothyronine.
Bloods 17th July were:
FT4 17.1 (10.8 -25.5)
FT3 3.4 (3.1 - 6.8)
No TSH result
At appointment 17th July she reduced my Levothyroxine to 75mcg daily and introduced 10 mcg Liothyronine to be taken in one dose in morning with Levothyroxine but I think she was going on the below blood results taken on 15th July.
If I take more Levothyroxine will it increase my T3 as well as T4? (I was previously taking 100mcg Levothyroxine 4 or 5 days and 75mcg 2 or 3 days a week, alternating those two doses alternate weeks as was planning to increase slowly to avoid palpitations from Levothyroxine).
(Lab wouldn't test TSH as tested two days before. The results two days before were totally different and yet I followed all the guidelines (fasting and no Levothyroxine or biotin) for both. In fact the bloods taken at endo appt were at 11am whereas the ones below (15th July) were taken at 8.45am).
Bloods taken 15th July were:
FT4 22.2 (10.8 - 25.5)
TSH 0.38 (0.27 - 4.2)
FT3 not tested
I am wondering should I just stop Liothyronine and increase my Levothyroxine to 100mcg instead? I did not feel as bad just on Levothyroxine (but I am a poor converter of T4 to T3 hence the introduction of Liothyronine).
My key vitamins are optimal.
For the first 8 hours after taking 5mcg Liothyronine I feel dreadful and then I feel better but still tired with brain fog.
Or I am wondering if I should ask my endocrinologist if I can increase my Levothyroxine to 100mcg every day and continue with just 5mcg a day but to take it at night? At appointment she instructed me to take Liothyronine together with Levothyroxine in the morning.
Sorry this is garbled and repetitive I have terrible brain fog and it's difficult to think and write.
Many thanks
Written by
1965Katy
To view profiles and participate in discussions please or .
Adding T3 raises fT3 it can't turn back into fT4 but it often reduces it
17th July...
Free T4 (fT4) 17.1 pmol/L (10.8 - 25.5) 42.9%
Free T3 (fT3) 3.4 pmol/L (3.1 - 6.8) 8.1%
T4:T3 Ratio 5.029
15th July...
Free T4 (fT4) 22.2 pmol/L (10.8 - 25.5) 77.6%
So I'm a bit confused but I'll give it a bash... with either of those results I wouldn't have reduced T4 before starting T3 and we always say only change one thing at a time
I'd go back to your previous dose of T4 and stick with that whilst you add T3... have you tried taking the T3 before bed as some find this works better for them?
Thank you for your help and sorry for late reply. I have been really struggling with my health conditions.
The 5mcg Liothyronine made me too unwell so I stopped taking it a week ago (14th August). I persevered for four weeks but the side effects became progressively worse. I have increased my Levothyroxine back up to 100mcg. I'm feeling like a bit of a failure. I did try taking it at night but it didn't help.
I am feeling a bit better but still feeling unwell. Not sure how long it takes to fully clear from your body. There is always the worry that this is caused by something else. I suppose it's a process of elimination.
I have tried to contact my endocrinologist but she is on annual leave until 4th September so I don't know what she will recommend.
I had a truly awful appointment today with a dermatology/lymphoedema consultant and I feel so angry. I really feel I have had enough of doctors. I am so sick of them telling me about my body and ignoring what I have to say when I am living with it 24/7!
Do you know if there is another drug I could try instead of Liothyronine?
Sorry to hear you are struggling with adding T3, often people that find it hard have very high or very low cortisol levels?
There isn't anything else as liothyronine is a hormone not a drug and is the same as your body produces, the only variation is the excipients in the different brands of T3, which brand of tablets do you have?
It's interesting that you mention cortisol. At the start of the year I had a series of blood tests showing high cortisol eg 805. I then had dexamethasone test and my results were back to normal.
My endocrinologist just recently ordered a Synacthen test which I am having next Thursday. Maybe I now have low cortisol or there is a problem my adrenals. It's strange that my cortisol was previously high.
Even if the test is normal I do not want to take T3 again as it made me so unwell. I am feeling infinitely better now having been off the Liothyronine for ten days. I looks like just Levothryroxine for me.
My understanding is that the adrenals initially kick in and produce more to make up for the lack of thyroid hormone and then as they start to tire produce less.
I'm thinking your reaction is likely due to the excipients in the pills as your fT3 is very low... perhaps it has been low for so long you need to introduce T3 more slowly to allow your body to adjust?
SST won't really tell you much other than if your body is able to produce cortisol
My fT3 has been low for a long time, several times below bottom of range. 5mcg Liothyronine made me so unwell, not just the usual anxiety and palpitations.
Yes maybe I should start at 1.25mcg and increase very slowly, alternatively try natural T3 Armour but I would struggle to pay for that. Or just stick with Levothyroxine.
The brand of 10mcg (split in half) Liothyronine was Morningside Healthcare. I have never been sensitive to excipients before.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.
Thyroid Results after 2 months
Update on Labs - What is Going On? :-)
T3 advice
Pregnancy & liothyronine
Need advise please before endo call as T3 above top range
