Thyroxine dosage according to your weight? - Thyroid UK

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Thyroxine dosage according to your weight?

Syd35 profile image
16 Replies

I had a private appointment today and the endo says that for my weight I am under-medicated on 75mcg, and has suggested I should take 100mcg / 125mcg on alternate days.

Has anyone else found going by weight is a good way to work out best dosage?

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Syd35 profile image
Syd35
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16 Replies
helvella profile image
helvellaAdministratorThyroid UK

Some time ago I produced a spreadsheet that calculates dose according to various factors - including weight.

dropbox.com/s/779n1uycxtujx...

It is, of course, nonsensical. Some people have very poor absorption. We even see people having different requirements depending on which make. And by season, activity and so on.

Having said that, if you have no thyroid function, it is quite possibly sensible to consider the minimum you are likely to need. And it just could be that weight could indicate that.

Syd35 profile image
Syd35 in reply to helvella

Interesting thanks :-)

Clutter profile image
Clutter

Syd35,

Estimating dose by weight used to be done for the starting dose of a patient after thyroidectomy, thereafter dose was adjusted according to blood levels.

shaws profile image
shawsAdministrator

I am not too sure about this method. If it works and relieves all of your symptoms that would be good.

However, many people gain weight when hypo before they are diagnosed, and also if dose is too low, so I am not sure whether the Endo would reduce dose if your weight dropped?

Syd35 profile image
Syd35 in reply to shaws

Yes I wondered this too as I managed to lose a stone last year but was on the same dose throughout.

shaws profile image
shawsAdministrator in reply to Syd35

If you feel good and no symptoms refuse to reduce dose if he should suggest it.

SlowDragon profile image
SlowDragonAdministrator

What were your blood test results? Presumably they also suggest you are under medicated

Syd35 profile image
Syd35 in reply to SlowDragon

Thanks SlowDragon, yes said I was under-medicated by my weight. I have posted results on my post yesterday that you also replied to. Thanks again!

Boohbette17 profile image
Boohbette17

Hi Syd35, I had the exact experience when first diagnosed I was 225lbs & the first endoI went to had me start 25mcg og levo - I felt like death by the time I saw my current endo - First wirds out of his moutn. Based on your weight alone you NEED miore thyroid hormone. A year passed on 150mg & after research I learned of cytomel . I had to plead my case that I wasn't converting ( based on labs) & he agreed to 50mcg of Cytomel as well. About in 3 months I felt like ME!!! As I want most energy during waking hours, I take Cytomel about 11a & Levo 11p...Works for me😆

Hugs!🌺

Syd35 profile image
Syd35 in reply to Boohbette17

Thanks Boohbette17 - glad you have found something that works for you.

Boohbette17 profile image
Boohbette17 in reply to Syd35

Thanks! in time you will too👌😊

We have viewed charts but they don't work, people are all different and should be tested on proper blood test results and symptoms. Your Endo is trying to simplify something that's not simply, sorry.

Syd35 profile image
Syd35

I tend to agree he even said it might not work which doesn't exactly fill me with confidence. Thanks for the reply.

SilverAvocado profile image
SilverAvocado

Although there are arguments against this method, it's very common to be left underdosed by doctor's simplistic measures. So if you have been offered a substantial increase, jump at it!

diogenes profile image
diogenesRemembering

The general approximate aim is about 1.8 mcg T4/kilogram body weight. But that's only an aim and it is of course important to modify the dose if it proves too much or insufficient. That figure is usually the one that clinicians aim for after total thyroidectomy to try to balance the patient.

Bonniet51 profile image
Bonniet51

That is not how it's done!! Blood tests show what TSH, T3 & T4 are. It never goes by your weight, never!! Find a doctor that knows something about hypothyroid/hyperthyroid and how to treat it. Report this doctor before he/she kills someone.

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