Log in
Thyroid UK
91,997 members106,252 posts

How to get 12.5 mcg thyroxine?

Hello, I'm new to this forum.

I need a 12.5 mcg dose of levothyroxine to fine-tune my intake, and would like to know how others manage this – is cutting the 25mcg tablet in half the only way? My chemist did it quite badly and the pieces are not uniform sizes. My GP says that 25 mcg is the smallest size available and there is no other way except cutting them.

Any advice welcomed!

10 Replies

Let's suppose that you want to take 87.5mcg Levo. To achieve this the simplest way for many people is to take 75mcg one day then 100mcg the next, then keep on alternating.

Levo is artificial T4 - a storage hormone, not an active hormone. In an ideal world the body stores the T4 in the body and converts it to T3 as and when needed. As a result of this absolute precision every day isn't necessary.

You may not be aware of this but some people take an entire week's dose of Levo once a week. It wouldn't appeal to me, but it works for some.


JMHW - as Humanbean says, alternating dose works well, I do it when I run out of a specific dose of tablets (I use 100s and 50s, always have more 100s so when I run out of 50s I take 200 one day, 100 the next, and get my 150 a day that way).

Or if you want to try a pill cutter, I have this one and use it very successfully on small T3 tablets so it should work on Levo 25s amazon.co.uk/Safe-Sound-Pil... but personally I think alternating would be less hassle.


Thanks for the pill-cutter link, I will try doing this!


JMHW I found the je most successful way of a clean cut is to put the tablet into the V shape and bring the blade down with a light touch. Too hard and the tablet might cut unevenly or crush, just a light touch should be enough. I cut T3 tablets into quarters and not wasted one yet.

I got my cutter from my local pharmacy, exactly the same as the one I linked to. Very happy for such a budget buy :)


If you take 25mg every other day for 14 days this equates 175mg decide this by 14 will equate to 12.5mg daily. Check with your pharmacy. I had to have a does of 87mg and this formula worked for me.


Thanks, but this dose is to take once a week, to fine-tune the overall intake. I was originally taking 50mcg daily, but it wasn't quite enough, so was prescribed an extra 25 mcg once weekly (i.e. 75mcg one day, 50 mcg the other 6 days) but that ended up producing hyper symptoms, so the GP proposed halving the extra to 12.5 once a week (i.e. 62.5). The absence of smaller doses in tqablet form (so far as I know) is making it hard to find a balance.


If you cannot take an increase of more than 12.5 mcg a week, then I would suggest you have a look at your nutrients, because that is not 'normal' (I use that word reluctantly, but it would seem there's something not quite right).

Have you had your vit d, vit B12, folate and ferritin tested? If you have deficiencies in these, then you will not be able to covert the T4 you're taking into T3, and the unconverted T4 can cause symptoms. :)


Thank you for your reply. My Vit D, B12, folate and ferritin are tested regularly and they are fine, no deficiencies – I take a range of supplements. Not sure why you think it isn't 'normal' that I cannot take a larger increase than 12.5 mcg weekly – the doses come in quite large increments so surely if the right amount for an individual to feel OK falls between two of the manufactured doses, they need fine-tuning. My basic dose is only 50 mcg daily, so any increase, however small, has an effect.

In the USA they manufacture smaller doses and work with smaller increments of increase or decrease. Unfortunately the system is different in the UK.


Because I've never heard of such a thing before.


Your pharmacist must be using a 'not too good' cutter. It doesn't have to be exact as levothyroxine has a long half life and takes about six weeks to gradually diminish in your system.

You can take one dose one day and another dose the next. i.e. some take 50 and then 75mcg and some even take one weekly dose.



You may also like...