Thyroid UK
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Starting thyroid s

I've been reading up on taking thyroid s ,just a little confused as to how much I should be taking. The ones I have are 60mg .Everyone is talking in grains.Am I right to think that each 60mg tablet is a grain and that if I wanted to start on half a grain I would need to cut the tablet? 

Can someone help me understand please 

I am currently on 100/125  of levothyroxine on alternate days.


4 Replies

You are correct that 60 mg = 1 grain.  To start on 1/2 grain (30 mgs), you would split your thyroid S tabs in half.


Thanks for clearing it up for me Phoenix 


1 like


1 grain (60mg) has 38mcg T4 and 9mcg T3 which is equivalent to 65mcg Levothyroxine.  If you start on half a grain you will become hypothyroid while you build up to the 1.75 to 2 grains equivalent to your current dose.

I would halve Levothyroxine dose to 62.5mcg Levothyroxine and introduce 1 grain Thyroid-S split into 2 daily doses for 2 weeks.

Reduce Levothyroxine to 25mcg and increase Thyroid-S by 1/2 grain (30mg) for two weeks. 

Stop Levothyroxine and increase Thyroid-S by 1/4 grain (15mg) for two weeks, and if necessary increase to 2 grains 2 weeks later.  Hold at 1.75 or 2 grains for 6 weeks and have a thyroid test to make sure FT3 remains within range.


I am not a medical professional and this information is not intended to be a substitute for medical guidance from your own doctor. Please check with your personal physician before applying any of these suggestions.


Thank you clutter 


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