Weight Loss

[jodary]

Have lost a stone in weight, is this likely to impact on dose of thyroxine ?

[helvella Administrator]

It could do. But don't suddenly make significant changes.

I have no idea of your weight or your dose! The example below is just an example working based PURELY on weight and dose:

If your original weight was 65 kg, and you were on a dose of 100 micrograms, that would be just over 1.5 micrograms per kilogram.

If you lost a stone (6.35 kilograms) that would mean a new weight of 58.65 kg.

If you stay on 100 micrograms, that would increase your dose to 1.70 micrograms per kilogram.

If you adjusted to the same dose by weight, you would need to drop to about 90 micrograms.

But I think it important to try to see where you are right now. Do you feel at all over-dosed? Did you used to feel right-dosed or under-dosed? Have you had a recent test?

And all of this is based on a very questionable assumption - that what you have lost actually required the same amount of levothyroxine as what is left. But this does seem extremely unlikely. Muscle requires more than fat.

[jodary in reply to helvella]

I am on 100mcg . Was 9st 10 and have just weighed at 8st 10 .. Am suffering from anxiety but that was the reason for the weight loss and am trying to eat more

[SlowDragon Ambassador in reply to jodary]

Suggest you get FULL thyroid and vitamin testing

For full Thyroid evaluation you need TSH, FT4 and FT3 tested

Also both TPO and TG thyroid antibodies tested at least once to see if your hypothyroidism is autoimmune

Very important to test vitamin D, folate, ferritin and B12 at least once year minimum

Recommended that all thyroid blood tests early morning, ideally just before 9am, only drink water between waking and test and last dose levothyroxine 24 hours before test

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip)

Do you always get same brand levothyroxine at each prescription

What vitamin supplements are you taking

[Bearo]

Are you sure your weight loss was due to anxiety?

If your dose of Levo was too high for you that might cause weight loss and blood tests should confirm this. (It happened to me on 100mcg - I felt good and lost nearly two stone over a period of eighteen months but blood tests showed my FT4 had gone over range and FT3 was very high so I had to reduce my dose. Fortunately for me I did not regain the weight and didn’t have any other symptoms of over medication)

[jodary in reply to Bearo]

Hi , I don’t feel good , have bad anxiety. Need to wait until January to do private blood test as gp will only do tsh. I’ve lost a stone through not eating, last blood test November showed high T4 low T3 so have had a slight reduction in thyroxine. Just need next blood test results before getting an appointment for a private endo. Thank you for replying