I took a private blood test last week (Blue Horizon Thyroid +10) mainly to get a FT3 result as the NHS isn't keen to do this any more, at least in my area (even though GP requested it). I wasn't too sure when to take the last dose before the test but was told to leave 24hrs in between dose and test, which I did. The result was 3.76pmol/L (3.1- 6.8). Although this is in the normal range it's not great? However, I have since read that, in the following article, it is more accurate to take the test six hours after a dose (I take four doses of 5mg T3-only per day = 20mg and have been on T3-only for seven years):
Any comments on my result and when to dose before a test gratefully received. Also, I have been playing around with the total dose for five months (lowering dose) trying to stop palpitations and had only been back on 20mg for about a week before the test. Would this have had an effect? So many questions!