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Thyroid UK
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How do you know how much T3 to take

Hello everyone, hoping that you can help with this. I am on 100mg Levo for last couple of years and to be honest I do not feel the slightest bit better if not worse. I would like to try T3. Is this used in addition to levo or in place of and what strength to start with. Going to try and get a private prescription and will pay whatever I have to to feel better. Thanking you

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A combination of T4/T3 can work for many. I have read that a combination of 3 to 1 was recommended.

Others who don't improve can also trial NDT or T3 alone.

It is trial and error as what suits one doesn't suit another.

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Thank for your reply Shaws. I am sorry to be so ignorant of T3 NDT etc. I have seen T3 supplements advertised on the net is this the same as the T3 that Docs were prescribing


I would only source liothyronine (T3) through proper sources. Otherwise we could be buying anything but not what our body needs.

NDT stands for natural dessicated thyroid hormones which was the very original in use in various forms since 1892. Before that we died.

Big Pharma through its promotion through monetary rewards for prescribing levothyroxine and blood tests have spent lots of money with the result that I think every country in the world prescribes levothyroxine and believe that it suits everyone. It may be fine for a majority but not for the minority whose body doesn't recover. T3 (liothyronine) is the only active thyroid hormone and doesn't need to be converted into T3 from T4 (T4 being an inactive hormone i.e. levothyroxine).

It is a big learning curve but if you are looking for T3 or NDT (it contains T4, T3, T2, T1 and calcitonin) you'd have to put up a new post asking for a private message to be sent to you as nothing is permitted on the forum of how to source prescription medication without a prescription.

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thank you that explains alot. Is NDT prescription only too. I understand re forum regulations. And yes its a big learning curve. I just want to feel half decent. I worked full time till I was 70 and looked after my Mother who also had Hypothyroidism and B12 deficiency until she passed away in February. Now its me time and I am a bit frightened to travel too far feeling the way I do. Although Mum lived till 94, I watched her suffer for years and feel I am going the same way. Sorry for my rambling. Must be a feeling sorry for myself day!!


What to do if you source some T3, is add a 1/4 tablet to your T4 dose and every two weeks increase by a 1/4 tablet till you feel much better. You take pulse/temp before beginning and if either rises too high drop to previous dose which should be your optimum dose.

If you source NDT it is measured in 'grains' usually and you switch to an equivalent dose. I believe 1 grain is approx equal to 100 levo and after two weeks, increase dose by 1/4 tablet as above.

Bear in mind I'm not medically qualified but that's the procedure I've read. Dr Lowe's widow looks after Thyro Gold which is a non-prescription NDT which he developed expressly not to need a prescription. I don't know how much it is.



Before considering any changes, you really need full thyroid labs :




TPO antibodies

Tg antibodies

vit d

vit B12



You need to know exactly what is going on with your thyroid, and you won't know that with just a TSH test, whatever your doctor says!

If you started T3, you wouldn't jump in with the full dose, any more than you did with levo. The rule for all hormones is : start low and work up slowly.

However, as you are only taking 100 mcg levo, the odds are that you are just under-medicated. Nothing will 'work' if we don't take enough of it. And T3/NDT won't 'work' if you have nutritional deficiencies. Hence all the tests. :)


Did you receive my reply Greygoose it just disappeared from here


No, I haven't seen a reply. :)


oh dear here we go again modern technology! I had blood test at surgery in March no change to prescription. Which shocked me as i felt so bad one week this, next week that, and so on never ending cycle of symptoms. I had the private bloods you mention done last week and all is okay even the antibodies are reduced from last private test. thank you


I take it those are the results below? Well, they're not all ok, are they, the FT3 is too low, so you do have a conversion problem. And your vit D is also too low. Are you supplementing that?

Your FT4 is a bit on the high-side, so you would need to reduce your levo by 25 mcg, and add in 6.25 mcg T3 - or perhaps 12.5 mcg. And you can increase every two weeks until you get to one whole tablet (I'm taking the tablets as 25 mcg but if you get them in the UK, they will be 20 mcg, so the starting dose would be 10 mcg with a reduction of 25 mcg levo.). When you get to 25/20mcg, hold for six weeks and retest. :)


Thank you Greygoose. I will start Vit D supplement. I did see it was a bit low. living in Scotland I guess we don't have much sun.


Plus you are hypo. :)


I know i would be wasting my time trying to tell Doc i need an increase. the figures are all in range. another reason to give T3 a try. thank you


They don't understand that hypos need their FT3 higher than a euthyroid person. So, for them, anything in range is just fine! Besides, you don't want an increase in levo, because your conversion would just get worse.


Thank you.

You all have so much knowledge. I am so grateful for all the information imparted. I feel I am so much better armed to stand up to my Doc.


That's good. :)


Can you add the actual results and ranges. Presumably you had vitamin levels tested too.

Dr Toft, past president of the British Thyroid Association and leading endocrinologist, states in Pulse Magazine,

"The appropriate dose of levothyroxine is that which restores euthyroidism and serum TSH to the lower part of the reference range - 0.2-0.5mU/l.

In this case, free thyroxine is likely to be in the upper part of its reference range or even slightly elevated – 18-22pmol/l.

Most patients will feel well in that circumstance. But some need a higher dose of levothyroxine to suppress serum TSH and then the serum-free T4 concentration will be elevated at around 24-28pmol/l.

This 'exogenous subclinical hyperthyroidism' is not dangerous as long as serum T3 is unequivocally normal – that is, serum total around T3 1.7nmol/l (reference range 1.0-2.2nmol/l)."

You can obtain a copy of the articles from Thyroid UK email print it and highlight question 6 to show your doctor

 please email Dionne at


Also ask for list of recommended thyroid specialists, some are T3 friendly. A private prescription would enable purchase of French or German T3 legitimately

Professor Toft recent article saying, T3 may be necessary for many



Hi SlowDragon

TSH 0.71 0.27-4.20

FT4 18.60 12.0-22.0

FT3 4.82 3.1-6.8

TPO 62.0 less than 34 (LAST TIME 121.5)

Tg 136 less than 115 (last time 393)

Vit D 51 def less than 25, insuff 25-50

B12 531 2 monthly injections and i supplement daily with sublingual

Folate 17.70 8.83-60.8

Ferritin 147.0 13-150

numerically these seem ok but still feel no different


100mcg Levo = 20mcg T3, though there are different equivalences used by other users of this site. Make small changes gradually such as just changing half of your Levo to T3. You may need to divide T3 into two doses, best to do this first anyway, or start 3ven smaller and exchange 25mcg Levo to start with, until you know how your body reacts to it. Good luck


Thank you so much Aurealis. You all have such great knowledge on this site.

So helpful always

I will take it slowly that is if I can persuade my GP to write a prescription

will let you all know how it goes

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