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Thyroid UK
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Am I on the right path with my T3 only treatment?

Hi everyone,

I am just wondering if there is an average dose of T3 only that seems to be optimal for most people or is it really quite individual.

I started T3 only in November and was doing well on it. I slowly worked up to 40 mcg which I have been on for a few weeks. I am starting to feel sluggish, lethargic and finding myself in bed a lot if the time again. I don't feel anything from my dose now- it feels the same as if I don't take anything to be honest.

I am tracking my vitals every day and it has been suggested that these show that I am still hypo but that my adrenals are coping with the dosage.

I might need to raise again but I am really surprised that I seem to have to increase as I did not think that I would need 40mcg never mind even more. ( I'm not sure why I thought this though!) I do remember reading a success story about someone who got their life back on 30mcg.

I guess I just feel nervous about increasing and wondering what dose I might end up on. There's always the worry about if I'm on too much! I don't seem to have any symptoms of RT3 clearance that some people report even though I've been on T3 only since November.

I haven't had any recent blood tests as I've been going on my vitals. Here is a sample of a days vitals:

T3 doses:

7am 20mcg

1pm 15mcg

5pm 5mcg


Time: temp: HR: BP:

9am 36.1 57 108/66

11am 35.6 57 105/70

1pm 36.2 71 112/61

5pm 35.6 68 110/59

19.06 35.3 75 107/73

Also, my digestion has slowed again and I'm finding it difficult to sleep at night again.

Does it look like I'm on the right path? I would appreciate anyone's thoughts.

Thank you

Carolineanne x

21 Replies

Doctors who were trained before the blood tests/levo were invented treated people according to their symptoms and increased doses NDT until they were better. Usual doses varied between 200mcg and 400mcg and three I know of said we were now given too low a dose.

I take my T3 once a day and am fine. I follow Dr Lowe's method: excerpt

Third, the leaflet on Cytomel pharmacies give patients when they fill their prescriptions states, "POSSIBLE SIDE EFFECTS: NO COMMON SIDE EFFECTS HAVE BEEN REPORTED with proper use of this medication." This information is accurate—when plain, full-strength, one-time-per-day doses of T3 are used properly, there are no adverse effects. The only adverse effects occur when a patient takes a dosage that for her is excessive. With Cytomel, if overstimulation occurs, it can be stopped with one or two small doses of propranolol. Or the patient can simply reduce her dosage of Cytomel the next time she takes it. I want to emphasize, however, that when our protocol is used properly, there is no overstimulation to be avoided by using timed-release T3. The protocol has safeguards against adverse effects.

And finally, why do I specify that the typical patient use one full dose of non-timed-release Cytomel for life? Because extensive testing has shown that this is safe, effective, and most economical—when used within the context of our entire protocol.


The purpose of T3 is to saturate our receptor cells.

Sometimes, it is difficult to know whether we are on too much or too little as symptoms can be similar.

I take my T3 once daily and have a normal life. The dose can vary from person to person. I know some people split their doses of T3 but I doubt it is due to a scientific reason but some might find it's better for them.

40mcg T3 is approx equal, in effect, to 160mcg levo. My dose is just over 30mcg but it is very individual to each person.


Thank you for the info Shaws :)


Everyone is different. I'm fairly sure the BNF states the usual maintenance dose as something like 20-80mcg per day so 40mcg is certainly not particularly high. I will see if I can find the exact figures. Of course we are all individual and I have just found out that my t3 is a little lower than I would like on 100mcg. I remember one member being on 160mcg per day due to thyroid hormone resistance.

Don't forget that larger people (like me ;) ) and very busy, active people (also me, lol) tend to need more thyroid hormone than other people. If you have any digestive issues you may find you need more than other people.

If you are monitoring all your vitals and you are being sensible with any increases, you should be ok. If you can find a doctor who actually knows something about this (they're not a myth, honest) then that's even better.

It does sound like you might be slightly hypo again. Perhaps your t3 is rather low in range at the moment.

I hope you find the answer. It's so frustrating finding the right dose isn't it!


Actually it's 60mcg in the BNF but in other countries I am fairly sure it is higher.


You are right. It is 60 mcg in the BNF and we get 20 microgram tablets.

Pfizer/King Cytomel says:

Usual maintenance dose is 25 to 75 mcg daily.


Cytomel is in 25 microgram tablets.

Could it have more to do with "three tablets" than what the person actually needs?


I suspect there is an element of having to give limits, just like with everything else in the world of thyroid :)


You could always cut the tablet in half, they're scored. :)

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Cytomel and Paddock liothyronine can be purchased in 5 mcg, 25 mcg and 50 mcg tablets. In theory this helps to titrate the dose accurately; in practice it's not economic for most people to buy the smaller doses. The 50 mcg is the best value, but splitting it into accurate doses is tricky - I used to make quite a mess!

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Thank you Carolyn. It is reassuring to know that 40 mcg is not high. It is difficult working out your dose. I will keep plodding on. :)


Just go slowly if you increase and if you feel worse, you know you have possibly gone the wrong way. It's a lot of trial and error even when you do have a good GP checking your levels to help guide you.

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When on t3 only, levels will not fully matter. Your blood may show it, but cells may not be recieving medication.


CarolineAnn, you need to have a FT3 blood test to check you are on a sufficient dose or aren't overmedicated.


Overmedication can cause fatigue as well as undermedication.



Yes that is my next step. They say blood tests don't mean much when on t3 better to go by vitals but I would still like to have a look. I'm also going to retest adrenals. Thank you :)


CarolineAnne, most advice recommends that testing is necessary and that FT3 should always remain within range.

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She is right.


I take 75


Is that your optimal dose Veggiequeen? Do you feel well? I think I will keep at it until I feel well. :)


My TSH was less than zero so my Doctor asked me to reduce to 50mcg which I did and I didn't feel as good. So I have gone back to 75mcg and feel much better. I have just started Thyro Gold as well to see if that wil make me even better.

I wouldn't recommend doing too many things at once. Try upping your dose gradually and leave two weeks in between changing anything.

I did feel a lot better yesterday after taking my vitamins which I admit I normally forget. So that could be worth looking at as well.

My temperature rarely gets above 36 and is normally 35.5. Your temperature may not recover but it is worth monitoring. Your Bp is pretty good.

The main trouble is with being Hypo there is no one size fits all answer. Which is what the Doctors want. I believe Dr Lowe took a daily dose of t3 that was much larger than mine. The other problem is that being overmedicated can give you similar symptoms to being undermedicated. Just go with how you feel.



Thanks. It's awful when the doctors want you to reduce and you feel worse isn't it? I guess the good thing about not feeling great is it forces you into looking at other things. ie: vitamins and diet. I am starting going gluten free to see if that improves things and making Kefir.

I have made sure my levels of vitamins are good but I know that my ferritin is not optimal so I will have to tackle that next.

Best wishes

CA x


I am currently on T3 only at 55 mcg and am yet to see major improvements. Have taken 6 months to work up to this amount so am taking it slowly. No doubt will have to keep on increasing as still have lots of symptoms.


For anyone who sees this.. I know this was posted a while ago, but wanted to share on this thread. I am currently on 180 mcgs of generic cytomel.. crazy. I feel okay.. I'm not heavy, so that's not the reason, but as someone stated for themselves below. Some people just need more. I've have gut issues and eating no carnmb diet.


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