I ran it for twelve weeks straight at 50mcg daily. Three weeks following cessation of the T3 I had comprehensive blood tests done by my endocrinologist. TSH and T3 were tested. All results were normal, healthy, and optimal. I DON'T RECOMEND THIS as everyones body reacts differently to every chemical on this planet. I have access to blood testing and an endo whenever and had preciously run it for 8 weeks with a follow up blood test stating that my thyroid came back just as normal. I don't think the problem is thyroid malfunction as most will preach, but rather muscle tissue loss should you use it for dieting purposes. In 8 weeks time on T3 and restricted calories/heavy cardio you can loose a significant amount of muscle tissue. This not only will make you look like shit, but will result in muscle weakening and a lowering of metabolism. Until you KNOW how your body reacts to thyroid hormones play it conservative.