Low TSH, normal Free T3 &T4: Hi, first post here... - Thyroid UK

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Low TSH, normal Free T3 &T4


Hi, first post here hoping I can get some advice. I have graves, had radio iodine 20 years ago. Been on steady dose of thyroxine since then, all levels normal. Last year my TSH began falling, now at 0.21, FT3 & FT4 mid range normal. My GP wants to reduce my thyroxine. Can anyone advise if they have experienced this and if reducing thyroxine makes any difference? Concerned my other levels will fall.

3 Replies


You are right, if dose is reduced FT4 and FT3 will drop and TSH will rise. TSH 0.21 may be below range but it is not suppressed. There's no need to reduce dose simply because TSH is below range as long as FT3 remains within range. Read Treatment Options in thyroiduk.org.uk/tuk/about_... Email louise.roberts@thyroiduk.org.uk if you would like a copy of the Pulse article to show your GP.

Elliecooper in reply to Clutter

Thanks for that Clutter! :)


Like Clutter says, reducing thyroxine will cause the TSH to rise and FTs to drop further. But why would you want that to happen, if your FTs are currently mid-range and you have no symptoms of being overmedicated?

Whenever I read about doctors wanting patients to reduce their dose of thyroid meds simply because of their TSH, I ask myself: is there any other disease known to mankind which makes doctors focus on one single lab result rather than symptom relief???

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