Thyroid UK
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Is there a rule-of-thumb ratio to work out a decent starting level for T3, having 100mcg T4 at the moment?

I've been scan-reading "Stop the thyroid madness"and been close to tears when I read how many of us have been fobbed off with pure T4. I only managed to get put onto T3 the first time because I went for regular consultant appt. and had to see a locum as His Nibs was out on an emergency. On seeing the fresh young man standing in,I took advantage of him and asked if I could at least give joint T4/T3 therapy a go. By the next time I saw His Nibs,my quality of life had shot up,I'd lost 9kg in 6 weeks and felt so much better. Even HN couldn't ignore the fact that I felt and looked better.

Moving on,I've decided to do 4 days@10mcg,another 4 @ 10 twice a day(8 hours between) and then hopefully 3 lots of 10 taken at the 8hr interval.6am,2pm and 10pm will be good times to put them in.

Sound a reasonable regime?

As promised,I've replaced my MRI avatar with a more human photo;I've had to crop out the 4week old kitten I was playing with at that time...aaaah!

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Rule of thumb is the prescribed amount you get. Optimal is how good you feel on the right dose.

I take 25mcg of T3 plus the prescribed 75mcg of T4 and feel better than I have for a very long time.

I take my T3+T4 before bed. I don't notice peaks and troughs throughout the day but I don't do much yet. If, when I'm more active I do experience dips I'll take additional T3 and will experiment with dose timing to find what's right for me.


Thanks for that. Whether it's all in my mind or not, I've felt better over the last couple of days on restart. I've also "perceived" that I'm okay for several hours and gradually tail off. The temptation is to attribute this to the free T3 being used up...Only time will tell. I will try again this week to get hold of my last blood test results. Wish me luck!


It won't be in your mind but lots of it will be in your brain, 'cos the brain is a big user of T3 :-D Your dips may well be due to T3 wearing off initially. When the T3 is replete in your cells the dips may ease off. Keep a diary of times, doses and peaks/dips. It'll help you if you need to rejig.


Diary's already started for just that purpose - thanks.


I totally agree ! I felt the same reading that on STTM website! That one & this one & another I've forgotten helped me heaps to find how to increase biggest mistake was forgetting that t4 has a much longer half life than t3 when I started dropping t4 & adding I'm finally feeling really good on t4 75mcg & t3 25-30mcg...I'm fighting hard to keep receiving t3 prescriptions (I do luckily have a years supply left!!) as my hospital & Endos don't like figuring out my blood test results Grrr ...but I figure if I have to live with cancer & need to take a high dosage than I'm going to have some quality if life while I'm doing it!! I also take 150mcg selenium & I split my t3 during the day!!


75mcg isn't a high dose, particularly if you've had TT. It works a lot better with T3 though, IMO. I'm not quite as suppressed as the endos want but I feel better on this lower dose and don't want to feel crap for years in case of recurrence.

Haven't they managed to get rid of the cancer Rose? I had RAI after surgery & have been clear 2 years. I'm hoping to get my thyroglobulin result tomorrow but was late testing & it might not be ready :(


Hey there Clutter! No they haven't :( I'm really sad/cranky/frustrated at the moment as my recent scans were clear but tg up at 18.6 suppressed. The PET scans showed a new tumor in hemipelvis but surgeon thinks its just my ovary (having surgery on Wednesday) I have 2 nodules on lung, adrenal gland 1.9cm, liver 4.8cm and nothing showed on RAI scan or pet as they're trying to find it but no luck...I'm going to try to increase meds slowly as I can't seem to get it past 75mcg & 25 mcg...upping t3 every 2 wks now to try suppression therapy...any hints I'd love to hear :))


Rose, T3 will suppress TSH, that plus T4 might just about be enough to suppress TSH <0.1 which is supposed to be ceiling for ThyCa.

If you struggle to tolerate T3 increase you'll need to take it very slowly. Cut tab in half and take extra 12.5mcg every other day for a week, then every day 2nd week, 25mcg every other day week 3 and every day week 4.

I'm so sorry to hear what's going on with you, you must be climbing the walls with anxiety.

I hope surgery goes well on Wed. Please let me know how you're doing when you feel up to it xx



Can I ask a lame brain question. I am fairly new to t3 - I have been taking 5mcg of t3 in 2.5 capsules (special order from Martindales), however I want to increase my t3 and my GP has agreed and provided me with 20mcg tablets which I will have to cut into four. I am finding this very difficult because the tablets are tiny. Is it taken as read that this is not an exact science and that some doses will be slightly more than say 5mcg (in my case) and sometimes slightly less. By the way I believe there is only one supplier of t3 in UK but maybe I am wrong?


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As far as I'm aware Mercury Pharma are the only producers of T3 in the UK.

Cutting the tabs will mean that the doses are not exactly 5mcg. It wouldn't matter to me, I'm not sensitive to slight variations.

Before I was prescribed Levo I was on 3 x 20mcg T3 daily. I didn't have any adverse effects.

Have you tried taking 10mcg T3 in one dose? You're accustomed to 5mcg so it shouldn't be difficult to tolerate. If you feel over medicated, while unpleasant, the short life of T3 means it will wear off in a few hours.


You could try asking for 5mcg Liothyronine tablets.

My prescription is for 2 x 5mcg twice daily and Boots supply bottles of 100 tablets manufactured by Paddock Labs in the USA.


Hi Clutter & mumcat1....before I forget Clutter do you know roughly how much T3&4 I should be taking to try to suppress to <0.01? I'm aiming for total 260mcgs per day? Is that too much or not enough?i can't really find info on this anywhere, only regarding feeling ok or not but I don't want to cause myself harm by going to high, or is that not even possible withough a thyroid?



Rose the dose required will differ according to weight, individuals. Raise your dose in 25mcg pweek so as not to give your system to much of a shock.

200mcg Levo meant my TSH was undetectable. 175mcg TSH was 0.01. 150mcg-100mcg it was 0.03.

I felt very ill being so suppressed and much better when TSH rose to 0.03.

20mcg T3 is roughly equivalent to 50mcg T4.

How did the op go and how are you feeling?


Hi clutter! Feeling not too bad & I can go home tmrw...not sure if I've replied or not...(brain fog + heavy duty pain meds = I don't even know my name! Lol...surgeon said he's never seen anything like it in over 25yrs...he said the ovary was haemoraging everywhere, there was a large mass & it was covered in cysts, size of a rock melon...he said if he didn't take photos of the ovary in Oct he'd never believe it was perfect then..he said it was as though after uterus etc was removed the last ovary went berserk with whatever it is!!! I wait for pathology!!! TSH & TG the same thing? I know it's my tg that's high to flag the 'active cancer spread' diagnosis...but maybe then it's my TSH that needs suppressing to drop the tg!? Hope ur doing ok!! I love reading your replies!!!


Thanks Rose :-D Ugh your ovary sounds a fright. How quickly things can deteriorate. You sound compos mentis and this is your first reply.

TSH is what the pituitary puts out to stimulate thyroid to produce T4. Tg is thyroglobulin anti bodies, measured after your TT as a 'cancer marker'. If it rises it indicates that thyroid cells are somewhere in the body. Weird that yours didn't take up RAI. Any idea what they intend to do?

I hope you're well enough to go home and are managing to get some rest.

Jackie x


Good luck wishes winging their way to you for tomorrow! Hhow long do you expect to be "in dock"?

Keep us up to speed when you are up to


Thank you very much mumcat & clutter...I'm not sure how long as surgeon doesn't even know exactly where it is ...and what he will take out...sing the ABBA song..."here we go again, why? Why?" Lol cx


Good luck tomorrow, Rose xx


Oh yeah not sure if you've worked it all out but t4 & t3 combined equal the same as the t4 you were taking or on now...I'm not sure what you were on when you felt great or if you are planning to increase...I was on 100mcg also then added up to 40mcg t3 which was too much & I got so sick! As that is 260mcg total...which is when I started to drop the t4 down & start again...(t3 10mcg=40mcg t4)...sry if you knew all that I wasn't sure :)


Oh I'm on beta blockers too for heart rate...just incase !!


Thanks for your words of wisdom Rose. Coming back to thyroid issues almost 20 years after believing I was happily settled on my meds, I'm out of the thought patterns I once knew well.

I'm sorry to read of your cancer issue. It's only ever affected me twice; I was very lucky to be in the right hands at the right time to receive what was then world cutting-edge (nopun intended)surgery and radiotherapy. I'm now on the receiving end of their effects because in curing my tumour, healthy tissue had to be sacrificed from my pituitary. I was warned then that I'd have these problems as I got older, so it's no surprise.

You say that you take beta-blockers - me too. It was prescribed when I started off with Graves, because of the tremor. Somehow nobody took me off it and when it was realised, I tapered it off only to regain the trembling.

Perhaps we ought to have topic called "I take more tablets than you", so my 41 + 1 injection (only 16 different medicines though) can have company!

Something that has really made me accept that that is how it must be was having the brain haemorrhage/stroke last year. It's also highlighted thyroid again because until very recently I'd put many of the symptoms I'd assumed were part of my recovery as time curable. They are not so jump back on the thyromobile!

All the best.


All the best to you also! It's great to know we're never alone :)


I was on 150mcg t4 when all my tests looked good but I still felt rough, so my doc gave me a script for t3 which I started taking daily at 6am. I'm a bit cautious about meds and was afraid they might make me feel anxious or otherwise unwell; I wanted to take it slowly, so I took 5mcg to start.

After a week or two I upped it to 10, then waited a week or two and upped it to 15, which is when I think I began to really feel it. (At some stage my t4 was reduced to 125 but I'm not sure when that happened.) Eventually I felt great at 20/25 daily (according to tests I may have been slightly overreplaced but had no hyper symptoms except for a bit of an overactive bowel). I went back to vigorous exercise, helped someone move house (slinging heavy boxes around, etc) and felt better than I had since the ht kicked in just over five years ago.

When I felt well I was on the equivalent of far more t4 than I had been on when my tests looked so good, so while I understand the 'equivalent' argument (1mcg t3 = 4 or 5 t4) I was on far more 'total' of thyroid hormone when on the combo (I guess my combo when at its highest was meant to be like being on 250-300t4, even though on paper 150t4 alone 'should' have been ideal).

Adding t3 until you feel better is a tough one because some people will tell you this is what you need to do and others quite reasonably will tell you that this can lead to taking too much t3 and damaging your health over time. I am still on the fence about how to best do it. I'd love the right doctor to oversee the process but can't seem to find one.

I was well for about six months, two of which were really excellent, then I seemed to go v hypo and haven't been able to get the right dose ever since. Some benefits of t3 never went away - even though I don't feel great right now, I no longer have horrible oedema or constipation, and it only took a v low dose for that to improve. As long as I'm close to what was my optimum dose, I wake up more easily every morning and I get a great night's sleep. So even a small addition of t3 is worth it for me and makes me feel far better than t4 alone ever did. I'm still chasing the elusive optimum wellness I had last summer though.

Good luck. In my experience the combo is much better than levo alone.

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