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How important is it to take levo at a certain time each day and why?


My dose has just been reduced from 150 to 125mcgs due to overtreatment.

I travel a lot and I take my thyroxine at all different times, sometimes after dinner sometimes morning. I just cant keep the time constant. Could this have a negative effect?

I've been really forgetful , I dont know if thats the overdosing.

My results a few days ago were TSH 0.02 (0.1-4)and free T4 25.8(11-21) and they have reduced my dose since yesterday to 125mcgs.

15 Replies

There have been tests conducted and it was found that it made little difference if levothyroxine (an inert storage hormone) was taken as one dose, once a week.


This method might suit you better if you are travelling it was said that patients, on the whole, preferred it.

G x



I believe that it is a good idea to be consistent.

Bear in mind that there are quite a few here who found a significant difference (often an improvement) by switching from morning to bed-time dosing. If it didn't matter, I would not have expected to see many say they felt different.

If you want to try weekly dosing, well, I certainly have doubts. Suggest you read all the comments on galathea's link.

If I remember right, you have also been taking different makes? That could most certainly have an impact. The recent MHRA Levothryoxine report points out that UK requirements for potency are 90 to 105% of labelled claim. If you switch between makes, from one which was towards the bottom of the range, the other towards the top, that could be very noticeable.

It's all very well calling thyroxine an inert storage hormone, but so many tissues do at least some local conversion of T4 to T3, that the T4 levels can still be very important.



Hi Rod. thanks yes I've been taking thronorm from India in a one tablet dose of 150mcgs.

Since yesterday I have the NHS mercury pharma 125mcgs split into 2 tablets.

I didnt realize the thyronorm could have been stronger. I loved the fact the dose was all in one tablet.

It seems scary to take 125mcgs x 7 in one dose. I'll check with my endocrinologost before i do that. If its ok it would be easier!


Well, remember that Teva was very much under-specification in what it was delivering before it was removed from the market. The differences between makes can be significant and the recent MHRA paper shows that the problem exists between the current UK "brands" - and I simply cannot see it being any less the case anywhere else (e.g. India) except in places sticking rigidly to USA FDA standards which are a bit tighter.

I too would be scared about taking a weekly dose.

Without access to good documentation, I don't know how they changed over to weekly dosing either. Stop for 7 days then take a full week dose? Or take a 7 day dose on top of a full system?

I think that you also have to question when you had the blood drawn for testing - was it after taking a dose? If you are not taking regularly, it can impact on the results you'd expect from a test. I, for example, skip my bed-time dose and make sure I get tested first thing in the morning (08:00). Then catch up by taking the tablet after the test draw.

Also difficult to know how weekly dosing will or should affect test results.


When I went to the pharmacy the chemist tried to give me 100mcgs of mercury pharma and 25mcgs of Wockhardt.

I refused it as I thought mixing the brands could be a problem.

Then he offered to order me TEVA.

Eventually he found 2 packets of 25mcgs of 25mcgs of Mercury Pharma to match the 100mcgs.

Was that right of me to get the same brand, does it matter?


Where and when was that?

Teva-branded/manufactured levothyroxine products were withdrawn early 2012.


(100 mcg had licence revoked by MHRA, 50 and 25 were withdrawn by Teva.)

If a UK pharmacist offered you any of their products recently they should be reported.

Mixing *shouldn't* matter. If each product works OK for you. After all, the potency issues can also be between batches!


It was on Thursday in a Numark pharmacy. I said I didnt want Wockhardt I wanted Actavis .

He looked it up and said 'Actavis dont make 25mcgs. 'And had I ever tried TEVA?

Then he found some 25 mercury pharma's which matched the 100's.

Also my endo said it was unusual for someone so thin to be on 150mcgs (I'm 5ft4 and weigh 8 and a half stone)

but it must be because i had high anti parietal cells for B12 deficiency. And 150mcgs was (at the time) an ideal dose.


Well he was right that Actavis do not make 25 mcg tablets.

You can see all UK products and some non-UK ones here:




By the way this is what I was taking


There is no obvious reason that this product would not be fine.

But some tablets do not deliver full strength dose to some people - varies by person, make, tablet dose, etc.

If you need 125 and were taking 125 but only getting 10% less than that (112.5), that was less than you need. So when you change to 150 which is delivering a full 150 to you, that could explain where you are.


Thanks very much for the link. I have never heard of that before. I do long haul flights every 2 weeks or so and always on different times zones and I cant be consistent every day.



What do you mean I'm on 100mcg levo so take 700 once a week ? That sounds really easy x


Yep, that's what they did.... Did you look at the links?


Will do thanks .


I just read the comments. And am shocked at the ignorance of some of the people commenting, The experiment conducted was with levothyroxine (t4)but people were talking about weekly dosing with t3 and t3 containing products, ( natural thyroid). This is a completely different ball game and taking the active t3 in a weekly dose is definitely not the same as taking t4 in a weekly dose. In fact it is a dangerous thing to do.



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