Difference between T3 and T4

[Iron man]

Which one is better?
Is there a big diierence between them?

 

[ohashi]

T3 is the active hormone. T4 is produced by your thyroid gland and is converted into T3 in the liver (well, mostly in the liver. I believe it can undergo conversion in a few other organs, but the amounts are not all that significant). By itself, T4 is if little to no use - T3 is the final, and active product.

 

[HGH man]

Most of the syntroid that people take is T-4. So T-4 is more common then T-3 . There are blends of both . I have to take Armour ,it has both T-4 and T-3 . I used to be on syntroid and felt a switch would be good for me. I has been. Which is better ? To do what ,lose weight ? Diet is better.

 

[Wrongun]

The two main thyroid hormones are T4 (thyroxin) and T3 (levo-Triiodothyronine). The thyroid gland mainly produces T4 which is later converted by a deiodinase enzyme to T3. The interesting thing is that T3 is about five times more potent at
raising the Basal Metabolic Rate than T4. In a dieting situation, the body produces less deiodinase enzyme, therefore producing less T3.
Without the effects of the more potent T3 the Basal Metabolic Rate decreases. Of course, there is plenty of T4 but it’s just not potent enough to
maintain the metabolism. With a lowered metabolism, less calories are burned on a daily basis and the diet ceases to work

Wrongun!

 

[Slyder190]

From what i understand, T3 is much more potent. I've seen guys complaining that T4 was a waste. Never tried either myself though.