Bodybuilders and athletes are attracted to liothyronine sodium for its ability to increase metabolism and support the breakdown of body fat. Eltroxin is very slow acting. Its plasma half life is about 11 days. That means that whatever dosage you take today, will only have an effect close to two weeks later. Furthermore, it takes about 4 weeks for it to reach stable plasma levels. It has a very highly suppressive effect on your normal thyroid action, even for 4-6 weeks after discontinuing its use. It is also poorly absorbed with a bioavailability of less than 80%.
Tertroxin on the other hand, works the opposite. It has a half life of only 12 hours, starts working immediately, does not have that lengthy suppressive effect on the thyroid after its use has been stopped, and more than 95% of the dose taken is actually absorbed.
