I have recently lost 23 pounds and wondering if... - Thyroid UK

Thyroid UK

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I have recently lost 23 pounds and wondering if I need to reduce my levothryroxine?


My heart has felt a little thuddy sometimes and don't know whether your size has anything to do with the amount you need? Its not the meds that have made me lose weight by the way, I have been doing slimming world for 3 months.

any advise?

thanks Tan x

22 Replies

Well done with the weight loss.

I found a formula the other day for how much thyroxine a body needed, I worked it all out and found I was just about right in what I am taking. Not sure where I found it but I've found the paper I worked it out on.

First, I converted my weight to lbs, then converted that into kgs, then I x that by 1.6. I think - only think - the formula must be 1.6 mcg of levo per kg of weight that gave me a daily dose of 91.36 levo and I worked out that over two days I am getting 87mcg a day which is a bit under but I feel ok. That doesn't take age into consideration though and I read somewhere that age is taken into consideration.

SO - see what you get when you do that - you could also do it with your starting weight and see what happens there too - maybe that will help you. Wish I could remember where I found that formula though.

Are you grumpy, shakey and running to the loo as well as thuddy?

Liz x

Hi Liz, thanks for that, just going to try that now. No, I'm not grumpy at all, really happy at the moment and nor running to the loo. My heart def feels funny every now and again though :(

going to pm you as I don't want everyone to know what I weigh....lol


Hi Liz, is it possible to send me the formula you use to convert weight into thyroid meds as Im on T4/T3 and have been on the same dose for the past 9mths,but struggling all the way so think I need an increase. Can you let me know how to pm you in order to send my email address.

Thanks very much

Sylv x

Have just pm'd you - that sounds really good, could I have a copy of that too please?

Liz x

helvellaAdministrator in reply to Fruitandnutcase

See my response to APsnotFab.

and me please xx

helvellaAdministrator in reply to mitchell66

See my response to APsnotFab.


Please don't say "very clever"! I simply have a background in such things. :-)


Please read the text in the spreadsheet!

Thank you, Rod.

Liz x

Southlondon in reply to helvella

That's really helpful thank you

moonbeam001 in reply to helvella

Thank you very much Helvella :)

RonnieG in reply to helvella

Wow! Thanks for sending this out it was very interesting - 2 1/2 years post TT (non-cancerous) I feel great at the moment but according to all these calculations I am 30 - 85 mcg too low on my dosage. I guess there are lots of other factors too and not everyone reacts the same. However, I will keep a eye on my levels. Thanks again.

A couple of years ago I went on the Exante Diet - very low calorie - and was losing a stone a month for a while. When I had my annual review (about 3 or 4 months of dieting) I mentioned to my doctor that my head was bobbing up and down like a little nodding dog in the back of a car, and my doctor also noted that my hands had a tremor. On testing my thyroid function, I had gone over-active and had to reduce my thyroxine. My doctor said it was to do with the weight loss as the amount you need is linked to your weight.

tingles in reply to DawnD

Hi Dawn, thanks for your reply, it kind of makes sense that that would be the case, I'm going to pay close attention and adjust accoring to how I feel, cheers for that x

ourida55 in reply to DawnD

This is very similar to me as last year I lost 2 stones at Slimming World and altho I was glad about my weight loss, I couldnt lose it from my tummy and always feel very overweight no matter what the scales say.. not lost any since I stopped going to the club at the end of last year and weigh a few pounds more now and creeping up. I was fed up of the continuing lack of energy and motivation for the past few years that I felt I needed to try T3 after a failed attempt 5yrs ago, as I was never offered an increase and taken off it after a couple of months. Anyway, even tho Ive been on 30mcg for the past 9mths Im not feeling that well and since retiring from work 3yrs ago after a long period of depression, my quality of life has gone downhill so I think my dose needs adjusting and I worry that my endo will want to take me off T3 again as he is convinced my problems are due to depression as I have had this illness on and off for the past 28yrs alongside my underractive thyroid. Please can you send any info you have re working out how much thyroid meds I should be on using my height and weight, which has gone up and down over the years.. I have never sent a private message before so can you let me know how to do that please..

Many thanks in anticipation...

Sylv.. x

tingles in reply to ourida55

Hi Sylv, a few replies up, Helvella has posted a link that helps to calculate how much t4 a body needs. obviously we are all different and every body is different x

Hello sorry to ask but could I have a copy too ? How do I send you my email address ? lol

ourida55 in reply to moonbeam001

Hi moonbeam, I wonder if you might send me a copy of this text as nothing happens when I click onto what looks to be his link. Do you know if this still works if taking T4/T3 combination as been on this for the past 9mths and thinking that I need an increase as still having symptoms. As taking T3 I know that blood test results can't be relied on and have not really felt much better, although taking 30mcg of T3 with reduced T4 from 150mcg down to only 50mcg. Was on T4 only for 27yrs and never well and in the past 4yrs was going downhill fast and now I need to know whether I need more or less thyroid replacement as symptoms can be hypo or hyper related I think.

Can you also let me know how to send my email address, as never sent a private message before..

Many thanks.. x

moonbeam001 in reply to ourida55

Hi Ourida,

what country are you from ?

I go to see an Endocrinologist on the 28th August hoping he will prescribe me T3 But things are not looking so good in the UK.

Here is my email address if you wish to send a message, sunshine9606@yahoo.co.uk

Many thanks.

Hi APsnotFAB I just saved it, thank you for letting me know :)

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