T3 replaced by Liothyronine sodium: Hi, I have... - Thyroid UK

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T3 replaced by Liothyronine sodium


Hi, I have been Levothyroxine and Liothyronine for over 20 years. In April this year my doctor withdrew the Liothyronine - without notification or consultation. I was finally given a telephone consultation with a doctor who prescribed my T3 but I have been switched from the natural T3 to Liothyronine Sodium, which does not feel the same. I am currently waiting for an appointment to get referred to an endocrinologist. Has anyone else had the same issue from their Doctor?

13 Replies

There is no difference between the two as far as T3 supply is concerned. The sodium part simply joins the rest of the sodium in your body. What may be different is the fillers making up the tablets which can affect absorption rates and possibly give allergy-type reactions. But this is nothing to do with the T3 supply itself.

Thank you for that info - I will bear it in mind when I eventually see the Doctor.



Are you in the UK?

I am unaware there is a "natural"T3. What exactly is it? I only know of synthetic T3 which is liothyronine sodium in most brands and liothyronine hydrochloride in Thybon Hennings (Sanofi-Aventis).

Yes, I am in the UK.

I only know that the endocrinologist I saw 20 years ago said the natural T3 was better than the synthetic. My prescriptions used to say "Liothyronine" and now the tablets are packaged differently and have Sodium in the name. I stick to a Slimming World diet 95% of the time but instead of losing weight - albeit at a very slow pace - I am now putting it on despite being stricter with the diet and excercising a little more. Plus I have nausea and headaches which I never had before.

in reply to hilaryclaire

hilaryclaire, the only 'natural' T3 is that which is made by a thyroid gland, or converted by a body from T4. So, either the endo was referring to the T3 that your own thyroid or body 'should' be producing, or perhaps to the T3 present in desiccated thyroid preparations (aka NDT).

Anything called liothyronine on a prescription will be referring to the synthetic version of T3.

The packaging of the tablets will be dependent on the manufacturer and distrubutor of the tablets. It may be that you are taking a different brand to the previous one, and that could account for your problems.

Check the main Thyroid UK website medicines page for info on the various brands and their ingredients. See here thyroiduk.org/tuk/treatment...

I was also both meds for about 16 years. I received a letter from the nhs commissioning group about withdrawal of Liothyronine, so i saw my gp as was concerned about not taking it. Although there are medical reasons, the main reason to me for this change is financial and costs of Liothyronine in the uk.

However i agreed eventually to trial a higher dose of thyroxine alone on the premise that i had monthly bloods for a few months and my gp would make a case if i needed Liothyronine and refer me to an endrocrnologist, all which i pushed for,if needed - before i agreed to stop.

I am now on thyroxine alone for over a year now, bloods are in range and i do feel beter overall not taking Liothyronine.

in reply to Dogholly

How did they withdraw the liothyronine? Did you feel side effects? I'm 2 week on a reduced dose and feel dreadful. How long was it before you were in balance? Thanks


Was your previous brand Mercury Pharma Liothyronine?

And now on Morningside Healthcare T3 or possibly even Teva T3?

Or if non UK Liothyronine due to cost, it can be several different brands and usually 25mcg tablets, not 20mcg

Just like Levothyroxine, Liothyronine brands are not bio equivalent for many patients

Some prefer one brand over another, and many find changing brands causes symptoms

Morningside Healthcare brand generally patients seem to find a bit stronger. Some prefer it. Others do not

Many many patients react badly to Teva Liothyronine

That's really helpful, thanks. I am on Morningside Liothyronine now but will have to ask the pharmacist what brand I was on before. The Levothyroxine I take is 100 mc from Mercury Pharma and 25 mc from Teva. I will check and see if the supplier for that has changed. Although I have just noticed the 25mc box has "New formulation" on it.

What does "bio equivalent" mean?

in reply to hilaryclaire

Many many people have had terrible reaction to Teva Levothyroxine.

Ask GP for new prescription for the 25mcg Levothyroxine and make sure to get Mercury Pharma every time

Bio equivalent means despite the packets saying they are the same thing and same dose, they give different dose and results.

So 20mcg of Mercury Pharma T3 will give different results compared to 20mcg of Morningside Healthcare

There's no such thing as "natural T3". T3 is Liothyronine Sodium (or hydrochloride in a few brands).

Hi just want to say I've been on levo for over 25years which wasnt doing anything finally this year some one gave me T3 which made a hell of a difference I added it to my levo was feeling great but that source stopped so went to endocrinologist and she has put me on liothyronine with my levo which I assumed is same as T3 but reading your post it seems like it's not? Is that correct? As I've been taking liothyronine for a week now been feeling great but getting real bad heartburn and stomach burning. Stopped it today the lio to see if it is that causing the heartburn.

in reply to Yazz1

T3 is the colloquial way of referring to the thyroid hormone triiodothyronine.

Way, way back, when first synthesised, triidothyronine as a medicine was call liothyronine - and it still is. This is almost, but not quite, universal. A few products round the world use the triidothyronine name.

The change from "liothyronine" to "liothyronine sodium" has been part of a process of more accurately identifying active ingredients. (The German product Thybon Henning actually contains liothyronine hydrochloride. But, so far as I am aware, it is the only product which has anything other than liothyronine sodium.)

We also saw "thyroxine" change to "levothyroxine sodium" (sometimes in one step, sometimes in two steps) - it is exactly the same substance, just a slightly more accurate and specific way of naming it.

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