How long does your body take to react to a levothyroxine overdose?

Question

How long does your body take to react to a levothyroxine overdose?

Answer 1

Good question. I found a good reference on the effect of a single large overdose:

http://www.ima.org.il/imaj/ar02apr-16.pd...

(it's a pdf file)

In this case it seems like the T4 and T3 peaked quite quickly and dropped off gradually, though the symptoms didn't seem to be that bad. From memory, the half life of thyroxine is at least a week.