Thyroxine or T4, is 300% less active then T3 thyroid hormone

Yup!

T4 or thyroxine, is your main thyroid hormone and is actually largely inactive in comparison to what T3 does in the body.

T3, or triiodothyronine, comes from the conversion of prohormone T4 which happens in the tissues of the body such as the liver and muscles, with a very small amount being produced by the thyroid itself.

This means, T3 production relies on the body’s ability to convert ample T4 to T3, nice biologically active hormone….. herein lies a problem.

The enzymes that help with this conversion have a lot of requirements for them to work optimally.  Conversion also relies on the functioning of the liver, muscles, kidneys and other tissues that are major sites for T4 to T3 conversion to be working optimally.

Further to this, ideally we need ample T4 in the first place to even possibly be able to make ample T3 to feel good…. Which is also a common problem.

How do we work all of this out?  

We actually do proper functional testing of the thyroid where we can look at all of these parameters.

By testing just one piece of the puzzle (commonly TSH), it doesn’t tell us anything about what’s happening with the rest of the hormone cascade and is commonly the reason why you can still feel rubbish, even if you’ve started on thyroxine therapy.

Get in touch today if you’re still feeling below your best but are being told… everything is fine.

Tash  xo