This is a relatively new Thyroid stimulating compound (aka T2 which is similar to the previous compound T3 which had undesireable side affects) that is proven to increase metabolism and burn lipids (fat) without the typical loss of muscle tissue. I would suggest caution when one begins to stimulate an active, normal thyroid gland. Do not exceed recommended doses. Four weeks on, four weeks off...NO exceptions (thyrotoxicosis is not something you want to mess with)! also known as: 3,5-Diiodo-L-thyronine or simply as T2.