Hi, I had intolerance to T4 Levothyroxine 20 years ago, the results of my ESR blood test then was that I had Inflammatory Arthritis, I was in extreme pain and had put on 5 stone in weight with the help of another Thyroid Web site I went on Armour Thyroid and have been symptom free for 18 years, however this became too expensive for me and 2 years ago I had to go back on Levothyroxine, the same thing happened again except I was on Levothyroxine for longer, I had put on 6 stone, pains in tendons and muscles and still have to walk with a walking stick, it has taken me a long time to try to get GP's to understand what the problem was, I eventually got to see an Endocrinologist, she put me on T3 combination with T4 for 3 months trial, I felt instantly better on T3 but for 3 months have still some pains, I saw the Endocrinologist a week ago, she took me off of Levothyroxine and put up my T3 to double it, for the last week I have been on 20 mcg per day and was totally ill with all the terrible side effects, my T3 prior to the increase was within the normal range, I reduced the T3 to only 10 mcg today and no longer feel dreadful. Has anyone out there had a similar experience? Are you managing on T3 only? I would be grateful for your help. Thanks.
T3 only diagnosis: Hi, I had intolerance to T... - Thyroid UK
T3 only diagnosis
Hi Denie500, welcome to the forum. 
I'm on T3 only but I take a lot more than 10 mcg! I take 75 mcg. But, I didn't get to that dose over-night. I built up slowly, 5 mcg at a time. You probably felt awful because she put you on too high a dose too quickly.
Hi, thanks for your reply this has helped me a lot. Previously I was taking 100 mcg of Levothyroxine, it made me so ill, how much T3 do you think I should be on as an alternative to 100 mcg of Levothyroxine? This Endocrinologist did not give me enough time to talk to her. Thanks.
No-one can know how much T3 you will eventually need. And talking about equivelents between T3 and T4 doesn't make much sense because there are so many variables. And especially as you didn't get on with T4. It's just not as simple as that.
What should happen is that the protocol is followed: start low and increase slowly, which means not by more than 5 mcg T3 every two weeks. So, ask your endo for an increase now, and keep asking until you feel well.
Hi, I've been on T3 only for 14 years. I take 50 mcg a day split into three doses. The Endos have tried reducing my dose on occasions, which hasn't worked as hypo symptoms return. I then have had to increase dose back up at 5 mcg doses, increasing at 10 mcg dose makes me feel unwell. Hope you feel better soon.
Thanks Yostie for your help. I am new to this Forum and am trying to navigate around this site. I had a lot of 'brain fog' on Levothyroxine as well as terrible pains in my body. As a rough estimate how much T3 should I be taking as a substitute for 100 mcg Levothyroxine. The Endocrinologist just wrote me a prescription for 20 mcg per day in two divided doses and said she will see me in a years time with a telephone consultation, I felt awful and just left to find out myself what to do. Thanks.
Hi, I can only speak from my experience, there are others here who have a lot more knowledge than I have. Reading research papers, blogs and more than a few books is where I have gained knowledge to practise on myself!
One particular place to go for T3 information is Paul Robinson; he has written several books on T3 paulrobinsonthyroid.com/ There is this post on his website re T4/T3/NDT, which you may find useful: paulrobinsonthyroid.com/pha...
Another very comprehensive source is Dr Sarah Myhill's website she has written the book The Underactive Thyroid - Do it yourself because your doctor won't drmyhill.co.uk/wiki/My_Book... ( I am not keto- paleo but am low carb, no added sugar).
My personal opinion is that with either T3 (or T4), it is about how my body processes T3 and that is dependent on my diet and other personal health and welfare practises. For me 50 mcg split into 20/10/20 morning early pm and bedtime works.
In my case for example: I have struggled for 30 years with iron deficiency and only in the last year taking liver capsules (I had been vegetarian and did not eat red meat) has my ferritin reached optimal, years of being fobbed off by GP, when I did not know for myself, then finally being given iron tablets, which if I stopped, my iron levels plummet. I was tested well below normal for zinc 25 years ago, then retested last year (special request as bio labs initially refused to run the test) to find Zn below reference range and, again, same with magnesium. Yet, I have been taking supplements and felt OK until in combination with severe stress and grief from a bereavement, I ended up at A&E with arrythmia, which has been a big wake up call and has got me back to looking comprehensively again at my diet etc. Mg and Zn both very important for the heart as well as thyroid. I am gluten free, 'correct' weight, physically active and test myself annually, privately (cos Doctors won't - for Vit D, active B12, folate, ferritin, and magnesium ). In harmonising my minerals again, after 9 months, the arrythmia has all of a sudden completely resolved
I think it is incomprehensible that you cannot get NDT on the NHS, instead they make you ill and it costs the system more, whilst your life is blighted.
20 mcg, on T3 only, is most unlikely to be enough. My dose at 50 mcg is the minimum I can live with and be OK. Hope this helps and don't let the Endo off the hook!
Thanks Yostie for your help. I have decided to not take any T3 for a couple of days and start again on Monday with 5 mcg in the morning and see how I go, the double dose of T3 just like that nearly killed me, I couldn't even think properly, the Endocrinologist did not give me the correct dosing requirements, I was taking 5 mcg in the morning with 50 mcg Levothyroxine in the morning and then another T3 in the afternoon at 5 mcg for 3 months and then the Endocrinologist took me off Levothyroxine altogether and just doubled the amount of T3 to 10 mcg in the morning and 10 mcg p.m. and I was so ill, I had chills, pains in my chest and had to be in bed with a hot water bottle and it was dreadful, at least with T3 the extreme pains in my body have stopped as well as now being free of Levothyroxine for nearly 2 weeks. Thanks for all your advice.
Same as GreyGoose. I've been on 75mcg T3 only for 20 years because T4 feels like poison to my body. If I've ever had to stop my T3 I always build slowly back up. Always reminds me of a car - you don't go from 1st to 3rd gear. Hope you feel better soon.
Thanks for your help Lily905. I will do as you advise and wait 4 days until the double dose too soon leaves my body and then build it up gradually when I get too tired I suppose. Thanks.
Yes. Just tune into how your body feels & don't rush getting up to a full dose. When I'm increasing or decreasing I either feel right or wrong an hour after I've taken my T3 in the morning. I felt too ill to eat on T4 & I went from a size 8 to a size 18 in a few months! Like you I've got joint problems & I can't carry weight. When I stopped the T4 my weight dropped because my eating wasn't the cause of my massive weight increase. Best Wishes
Hi Lily905, it sounds like a lot of people mostly women have had serious illnesses whilst being on Levothyroxine in my case I was diagnosed with Inflammatory Arthritis nearly 20 years ago, had put on 5 stone in weight and cognitive impairment (brain fog) all caused by Levothyroxine, 20 years ago I just bought Armour Thyroid from the United States but 20 years on can no longer afford it. After being on Levothyroxine for nearly 2 years this time I put on 6 stone in weight, terrible brain fog, Bursitis in my hips, swollen knees an absolute cripple. I read on the Internet from The National Institute of Medicine that Levothyroxine takes 4 to 5 weeks to leave the body, so far its been nearly 2 weeks. I am starting again with only 5 mcg T3 in the morning and none in the p.m. it was too much. Thanks for your help.
Your dose seems really low I take 40 mcg and feel ok at the moment sounds like your endo is giving you to much of an increase 5mcg at a time is best also do you know not to eat anything 1 hour after your medication and two hours if you have eaten something
Hi mspolly, thanks for your reply, are you taking T3 only and for how long have you been on T3 only? The Endocrinologist did tell me this about not eating as you said, I never feel like eating in the morning anyway so I leave having any food for 2 hours after taking T3. Thanks for your help.
Where can I purchase T3
Buying T3 online
T3 as opposed to levothyroxine 
t3 only or combination t3/t4
T3
