Why do doctors treat hypothyrodism with T4 and not T3 ?

**JasonR** · 11-07-2007, 01:49 PM

What is the reason for that ? half life ? risk of overdose ?
Thanks !

**Marek** · 11-07-2007, 02:31 PM

It is not uncommon for Doctors to use T4 as the body is supposed to convert the T4 to T3 unfortunately this conversion does not take place for some people.

**MuscleScience** · 11-07-2007, 03:46 PM

T4 is present 4X more than T3, but T3 is 4X more potent. T4 is converted by the targets cells to T3. T3 has a very short serum life in respect to T4. That is usually why T4 is administered in most cases.

**JasonR** · 11-07-2007, 03:50 PM

Any reason why I shouldn't replace my T4 for some cytomel ? im taking 200mcg's of this stuff already... 50-100mcg more and it will start to get pricey

**JasonR** · 11-07-2007, 04:43 PM

i should have searched
Why do doctors presribe synthroid over cytomel for thyroid conditions?

its amazing how every single question- even the weirdest has already been asnwered here