My pharmacist has told me the ratio of levo to lio is as follows:
25 mcg levo = 5 mcg lio
I do not know the conversion for NDT specifically - but helvella has published a table that you can find under “pinned posts” - and that will give you the conversions of all the different combinations.
I do not think nine days is enough to tell if NDT is working - it is my impression that you need to give it about 6 weeks to feel significantly better based on what others have reported on the forum. Please, if I am wrong about this, I welcome others here to correct me.
Hope this helps and I’m so sorry your muscles are still hurting. See how it goes for the next little while and I really hope your next report will be better. Sending you good wishes tonight.
Below are some discussion points meant to highlight the difficulty of ratios in relation to oral thyroid hormones. They are NOT realistic.
Imagine you take 100 T4 and you have excellent conversion, you might get 20 T3. Implying a ratio of 5:1.
Imagine you take 100 T4 but have poor conversion - say you get just 5 T3. Implying a ratio of 20:1.
Those with impaired absorption of T4 would see different ratios.
Imagine you have to take 200 T4 in order to absorb as much as most people can from 100. So you take 200 and using the same numbers as above, get 20 T3. Implying a 10:1 ratio.
Now look at it the other way round. Someone taking 200 T4 a day because of poor absorption and using a ratio of 5:1 might think they need 40 T3.
Someone taking 100 aT4 a day might think they need 25 T3 a day. But if they are surviving on just 5 T3 a day from conversion, that would be a five-fold increase in T3.
A classic discussion of endogenous T4 suggests approximately one third converted to T3, one third to rT3, and one third excreted. If you then assume that you absorb about 75% of the T4 you take (because your endogenous supply has failed), that would end up at a very neat 4:1 T4:T3 ratio. Too darned neat by half. But makes some sense if there are NO OTHER issues confounding.
Thanks, helvella. So a quesrion - so where would one begin dosing from scratch then if just starting on combo T4/T3 or you have never been on meds or is you are adding T3 to your T4? Is there some reasonable starting point? I have been curious about this. All the best.
I think so - I was started in T4 first alone and then endo added T3 when I was not converting. My quesrion is sort of hypothetical because of what helvella said because if everything I have read on the forum. I have seen so many different answers to that question and was hoping to learn something new! 🤗
This is the situation most people will be in when adding or adjusting T3. This is why we get the 3x or 4x as potent estimates. What Helvella is saying is more correct, but we have to have some rules of thumb to actually act on.
I always assume T3 is 4x as potent in my own dosing (so to add 5mcg of T3 you'd drop 20mcg of T4), but 3x seems to be more popular on the forum at the moment.
Thanks, Silver Avocado. I appreciate that insight. The ratio given to me by the pharmacist so far 🤞is working for me when I need to add T3 - we are all so different! And it really is trial and error too. But as many have said, time is needed to really see how any particular dose will work and in my experience, 6 weeks seems right to me. All the best to you!
Wouldn’t that be nice? But sadly, thyroid disease is not a sexy topic for researchers right now, so we will have to practice DIY medicine until something better comes along. 😕
75% absorption seems high. I thought I read recently that it was only between 40-60%? 🤷♀️ no matter I completely agree that there’s too many factors personal to each individual to warrant hard and fast rules but it does give us some idea.
FT3 will tend to be low if you are poor at converting. But FT3 alone is not sufficient to assess conversion. You need FT3 and FT4 from the same blood draw.
Someone who is poor at absorbing levothyroxine will tend to be on a higher dose than would otherwise be expected.
It would be possible for someone to take their levothyroxine and have a series of blood tests (e.g. every hour, or even more frequently) to show how their Free T4 levels change. If it does not rise as much as expected, and if the peak is delayed, it does rather indicate poor absorption. Trouble is, you are going to find it very hard to find someone to do the necessary testing.
Do note that my post was meant to illustrate the issues rather than be a set of numbers that really would occur.
I think my history shows very well that I’m not a good convertor. I do convert but not good enough. Most of my results have been ‘in range’ and so my GP’s don’t think any action is required.
FT3 (3.5-6.5) FT4 (9-24)
2014 sept 3.8. 15.2
2014 Nov 3.9 16
2016 jul 2.5. 6.6
2019 jan 3.5. 23.3
My history shows a clear conversion problem. I’ve tried time and again to increase my T4, only a few times has it actually show higher in range and my FT3 just never really rose.
I hope this helps. I wish I hadn’t waited so many years to build up a good history but I didn’t know any better. I wish I could have this history of results within a year instead of 4/5yrs.
I’m sorry to hear that your muscle aches got worse. Have you investigated other possible causes? I had a terrible time this time last year. I had been on levo for about a year and was finally getting somewhere, when I suddenly had a period of fatigue and dreadfully dead achy legs, as if I was coming down with flu. I tested for vitamin D, b12 folate and ferratin, as often suggested by our forum experts. They were all low, especially b12, which was a great surprise to me because I have a good diet. I’m much better for supplementing. Hope you get to feel better soon, it’s a long journey with many stop offs along the way. 🙂
I’ve just had a nosey at your old posts and noticed that you follow a vegan diet and also have tinnitus - both highly associated with vitamin b12 deficiency. You should definitely explore this option, even if you already supplement b12 orally. Hypos are known to be poor absorbers in any case, and those with Hashis are at increased risk of developing pernicious anaemia, which is another auto immune disease that destroys the body’s ability to absorb b12.
When we take thyroid hormones it is different than taking a paracetamol. First the hormones have to be absorbed and it takes sometime to build up to a dose which relieves symptoms. This can take a few months and the aim is a TSH of 1 or lower and a FT4 and FT3 in the upper part of the ranges. Levothyroxine is an inactive hormone. It has to be converted into T3 which is the Active hormone which is needed in our millions of T3 receptor cells.
Initially we take 50mcg of levo and an addition of 25mcg every six weeks until our symptoms are relieved.
You were lucky enough to get loads of advice and long posts from members, with most telling you not to chop and change your dose. You then cut and pasted a reply to all the comments saying you would be ignoring the advice.
My advice this time is broadly similar. If you want to treat your hypothyroidism, choose one treatment, it could be Levothyroxine, it could be NDT, and stick with it for 4-6 months. Every 6 weeks or so get a blood test and adjust your dose, until the tests look optimal and/or symptoms are resolved.
After a few months, if you haven't got any improvement, then that is the time to consider moving on to a different form of thyroid treatment.
After a few weeks, and before you've tuned your dose fully, you will likely feel worse. This is a long process to get better, and part of finding your perfect dose is that you may feel worse for some of the process.
Chopping and changing every few weeks will not get you to a point of feeling better. It will just waste your time, and once you've run out of options you will have to go backs to square one and start dosing yourself sensibly.
You've been told many times in both threads, your assessment is incorrect. Many people will feel worse on an initial starter dose, but this doesn't indicate that the treatment won't help them. It's a necessary phase we have to go through to hopefully feel better in the end.
Everything with thyroid hormone takes a long time, and we need a lot of patience to get better.
Chopping and changing dose will not enable you to find an optimum dose. Slow and steady is better than 'chop/change' the emphasis being gradual relief of symptoms. Maybe this will help.
I must say that following the advice of this board to get all vitamins optimal, take meds optimally, make small changes, slowly, and give each new dose six weeks to "bake" has led to me finding a dose (a bizarre 75t4/30t3 ratio) where I feel better than I have in decades. And I am not a patient person, so I am really, really glad I was patient!
I have been the combination for many years, my current dose is 200 mcg of T4 and 20 mcg of the T3 (lithyronine) but everyone is different - I have been on meds all my life, but only the combination in the last 15 years or so, may be more.
Can I ask why you want or been advised to have the combination? Your T4 levels seem to suggest you need more T4, first, as the 50 mcg is very low and only a starter dose. Most people seem to be ok on 100-150 mcg of T4 especially later in life.
T3 is normally given only after T4 fails to work properly and is very hard to get if you live in the UK as unfortunately it is very expensive. Most of us have to fight to stay on prescription an rarely new patients are prescribed it.
Initially you should be having blood tests every few weeks to check the results and make any changes accordingly.
Don't ever stop your meds, as they are for life now follow your medical advice.
Out of interest have you had your folate and ferritin levels checked for B12 and Vitamin D deficiency and also iron and pernicious anaemia? They have similar symptoms as thyroid conditions and can walk hand in hand, especially B12 deficiency and pernicious anaemia.
I am currently self medicating with ndt. A decision I did not take lightly. Looking back at your previous posts you seem to be hoping for more than any medication can deliver in such a short time. When I saw your T3 was so well into range I was shocked to note to intended to add it rather than increase T4 which was low. You have been given excellent advice on here by others who clearly have an amazing understanding of thyroid function and related meds. I cannot understand why you have chosen to ignore that excellent advice. In the long run you will probably only make your situation somewhat worse and have to accept the process of feeling better is a long one. I have had nearly sixty years of taking medication for hypothyroidism. Initially I was treated with ndt, this changed many years later. I had suffered from such debilitating symptoms I needed to address these. The NHS was unable to offer any help. Having discussed with the GP my intention to self medicate over a period of several weeks I went ahead, with some trepidation. This after spending all those years looking at the condition and how it affects lives. It really worries me that you are taking this path without understanding what it can mean, and for no logical reason. I only hope you can handle things a little better from here on.
The ratios are based on an average, but real people are far more diverse. So, no, you don't need to do that. The idea is to get a dose that works for you, You should stay on one type of med for at least 3 months, pref 6, before deciding whether it works for you or not. TO know wht dose of T3/T4 to start on, you need to know your current results for TSH, free T4 and free t3
Crikey, the science here is great. BUT sometimes we are all so different, stuff just works, when it cannot be explained truly. We have such a complex metabolic problem that is affected by so many other factors unique to us. The admin people here are awesome and they make sense of what is fog to most.
I have been lucky to have an Endo with clout. Nearly lost T3 (NHS policy) but have muscled my way through with his help to keep on what has been a sweet spot 125mcgs T4 20mcgs T3 taken in two 10 mcgs doses at 9.00am and 3.00 am,
I found a Doc in the Thyroid UK members pack that also privately diagnosed Mitochondrial Disease often related to Autoimmune conditions. Some symptoms I had I associated with my Thyroid condition but were in fact those of Mitochondrial failure, diagnosed by blood test and now supported by suppliments. I know now, once you have an Autoimmune condition there is a more complex balance than just T4 and T3.
Sorry haven't read through all responses above, and don't know if anyone will find this info useful, but I read in the past that humans make about 6mcg of T3 a day. More specifically, I read that human thyroids have a T4:T3 ratio of 14:1. And NDT, Armour, etc has a ratio of 4.2:1. This would explains why NDT often needs to be supplemented by a bit of synthetic T4.
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