Thyroid UK
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300mg Levothyroxine ?

I had thyroid lobectomy 2008. Lab sample showed papillary cancer. The aim after operation was to suppress TSH to be undetectable and prevent a cancer on the remaining thyroid.Over 5 years on increasing levothyroxine TSH is now 0.77 but my T4 is way out of range at 46. T3 is 8. I am on 300mg levothyroxine and feel ok. I now have been told To accept failure to totally suppress TSH but concerned about long term effects of 300mg levothyroxine.

3 Replies

Before the TSH was introduced as a diagnosis patients were prescribed between 200mcg and 400mcg of natural dessicated thyroid hormone (which contains all the elements of a thyroid gland). Thyroxine is what a normal healthy thyroid gland produces and levothyroxine is a synthetic form of the hormone.

I am not medically qualified but as you are feeling o.k. on 300mcg levo I would not think it is detrimental to your health as we cannot live without thyroid gland hormone - T3 in particular.



I am no doctor of course, but I do know that T3 suppresses the TSH more effectively than T4. Is it possible to ask your consultant to try T3 as an alternative or in combination? It could be more effective re the need for suppression.

That would involve reducing your T4 and adding in some T3 sufficient to make you still feel well and suppress the TSH. Your ratio of T4 to T3 is such that it is possible you could benefit from this.

Your T3 level seems quite high, yet you say you feel well, so it would be good to get the ranges to see how that 8 sits in the range for the particular lab. If it is still within the range then you really do not need to worry, you will only need to worry about long term effects if the T3 is too high and you have symptoms of thyrotoxicosis. The issue, really, is that you are not suppressed as much as could be hoped.

Bearing all this in mind, I would think it could be worthwhile raising the matter with whoever is monitoring your health.

Hope this helps.

Marie XX



I was on 300mcg thyroxine for more than 25 years and I have never had cardiac or bone density problems which is the two concerns for GPs. Not until it was reduced did I start having palpitations. I am now going to ask for another Dexa scan (which has always been fine in the past). I have been hypo for the last 10 years. When I was put onto 300 mcg in the early 80s it was seen as a normal dose.



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