I have about 120 T4 tabs sitting in my house right now and I am planning on using them on my next bulking cycle to see if they help keep the fat off or help get a little leaner. So I don't know how it works compared to T3 yet, but I have also heard that 4-5X the dosage is needed. Just remember that if you take T4 you have to keep your carb intake up, carbs play a chemical role in the conversion of T4 to T3. So if you used T4 with a low carb diet you probably wouldn't notice much.

Pain