Here is some information on T2:

T2: 3,5-diiodothyronine (3,5-T2)



3,5-diiodothyronine (3,5-T2) is supplied as a liquid suspension for the convenience of easy, accurate measuring

It is offered at 1000mcg/ml concentration

100ml bottle

100mg total 3,5-diiodothyronine (3,5-T2)

$1.00/1 mg 3,5-T2

The isomer 3,5-T2 has selective thyromimetic activity and has an ability to suppress TSH levels. In animals, the 3,3'-T2 and 3,5-T2 isomers induce a dose-dependent increase in resting metabolic rate (RMR), an increase accompanied by a parallel increase in the oxidative capacity of metabolically active tissues such as liver, skeletal muscle, brown adipose tissue, and heart. In these experiments, 3,5-T2 exerted its greatest stimulatory effect on brown adipose tissue (BAT), while 3,3'-T2 had its greatest effect on muscle oxidative capacity. Although T3 is generally considered to be the metabolically active thyroid hormone, in contrast to these T2 isomers, T3 has only a small metabolic and oxidative effect on skeletal muscle and no significant stimulatory effect in heart and BAT, irrespective of dose.8,9 (See Table 1 for a summary of T2 isomer activity.)

Of the T2 isomers, 3,5-T2 is presumed to be the most metabolically active and can only be formed from further deiodination of T3 by 3'-deiodinase. The isomer 3,3'-T2 can be formed from the deiodination of either T3 by 5-deiodinase or from rT3 through the same 5'-deiodinase enzyme responsible for the formation of T3 from T4. rT3 can also be degraded to an inactive isomer, 3',5'-T2, by a 3-deiodinase enzyme.

3,5 T2 is highly effective in animals at burning white adipose tissue through increasing Resting Metabolic Rate and stimulating Brown Adipose Tissue (BAT) metabolism. For this reason it is less catabolic to muscle tissue than T3 and has a similar potency to T3 of overall fat burning/caloric expenditure capacity at dosings of approximately 8x the dose as would be administrated of T3. ie 25mcg T3 = 200mcg T2 for similar fat burning potency.


It can be found but quite rare.Who has used it? Why is it not used being less catabolic than T3?