I started taking levothyroxine around 15 weeks ago, and I've recently been on a still fairly low dose of 37.5mcg per day. In addition to this I was recently prescribed liothryonine at a dosage of 7.5mcg per day.
I understand that T4 and T3-based meds both work a little differently in the body, with T4 taking weeks to reach peak levels in bloods with T3 being a matter of days.
I've been taking liothryonine for nearly a week now, so would you expect any impact I'm going to see from this dosage reflect in my blood levels, or is this still too early? If so, should I expect symptomatic relief shortly after bloods are showing optimal levels, or is that still likely to take time?
Sorry if these sound like basic questions - I just want to make sure I have my expectations set correctly.
Written by
JonnyA
To view profiles and participate in discussions please or .
I just wanted to reply, and, to ask you a question...well three actually .....
1. How are you feeling on these doses of T4 and T3 ?
2. Have you had any recent bloodwork?..... if so, you might want to include a picture of the TSH results, FT4 and FT3 results, with ranges, so other members can comment, ie, advise you accordingly.
3. Are you taking vitamins/supplements, to optimize your Thyroid ?
I am not knowledgable like some members on here....but to me, these doses seem low ('starter doses').
It seems strange that they prescribed you t3 so early on. Do you know why? I would have thought it would be far better to have raised your levo first. That is a very low dose.
T3 for me was no immediate improvement. Personally and everyone’s different I get energy from t3 but my main symptoms seem to want t4. I take 25mcg t3 along with 125 mcg t4.
It’s very difficult to say what benefit you may feel. T3 will push your t4 down so you may find that if you take a blood test, you could raise your levo now and that may help with symptoms. Some people, myself included, seem to like higher levels of both. Strange but true!
The thinking from my endocrinologist seemed to be that T4 didn’t really want to go much higher, but that my T3 was still below optimum range (5.5 to 6.0 being optimum).
I see. I also see the reply from Tattybogle and didn’t realise you had only been on t3 a week. It is a slow process I’m afraid and I didn’t really notice anything for a couple of weeks and even then it wasn’t a ‘eureka’ moment. Lol.
When I started this journey people did say I had room for a levo increase rather than t3. However as I had been prescribed t3 I took it. 8 months on I am wondering how things would be if I dropped the t3 completely and opted for more t4. Even if that pushed me over range for t4 🤷♀️ And that’s the thing…. It’s trial and error with what suits you. We just have to keep believing we can feel better because lots do.
I think, knowing what I do now, if I were you, I would have opted for more levo first. Others may disagree but I would take a more stable t4 level (even as a poor converter) over liothyronine. The Hope being that a raise in levo dose may increase your t3 just enough to help you feel better without having to bother with both and if it doesn’t work add the t3 then.
The problem with doing bloods a week after adding T3 is that while you will no doubt see the added T3 in the blood , there is a knock on effect to/from the HPT axis (hypothalamus /pituitary/thyroid, regulating system), that has not had time to play out fully and then settle down again. So the results you see after a week won't tell you anything you could count on to be any indication of what your blood levels of fT4/3 or TSH will ultimately be like on that dose.
Oral T3 will be in the blood in a few hours , after a few days on the same dose you'll see the average level from that dose, but then it will all change . The hypothalamus will notice the extra T3 , that will change the amount of TSH that the pituitary sends out, That will change two things , the amount (and ratios) of T4/3 your own thyroid releases , and also the rate of conversion of T4 to T3 in the body.
So after another week or so , you'll have different fT4 /fT3 TSH results, and the HPT regulating system will recalculate all over again , and tweak what's a happening.
So you get all sorts of apparently 'odd' things happening to blood results .eg. often when you add T3 , it makes fT4 go down .
You could reasonably expect TSH to have 'settled down' by 6 weeks , but to be honest , we are all different and no one really knows .. it's not like anyone in the real world tests full Thyroid bloods every every week after a dose change to really see what happens. .
But '6 weeks' would seem to fit with what many of us notice in practice , (as you did when first taking 25mcg Levo) ..... you feel not much for a few days , you have 2/3 weeks of feeling significantly better , then you go somewhat downhill again.
Based on my experience of several consecutive dose adjustment on myself ,, i would now wait 6 weeks minimum for first blood test on a new dose , and also would actually wait more like 8 -12 weeks to see 'how it felt' once settled.
Sorry to be so boring .. but it think it's the truth.
"Don't push the water .. it flows faster by itself"
JonnyA, we often don't have males joining the forum especially with a predicament such as yours. You are fortunate to have three thyroid tests taken although I'm in the U.S. and it is more common than in the UK. Functional doctors even consider Total T4 and Total T3. It makes sense to me to look at all the values of the hormone. If you care to get a more holistic view of what goes on when your thyroid becomes dysfunctional ......even caused by an extremely low calorie diet....by outside factors, here is a discussion between two functional doctors you may find interesting.
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.
Getting a thyroidectomy soon, what to expect?
How long is a piece of string (aka am I hyper or hypo)?
How much T3 should I take?
What level should my Free T3 be?
