I have read on a board that T4 dosent really supres thyroid because the conversion in T3 is still made in the body and that the body dont give a shutdown signal.Is this really true?I know T4 it is aint that good as T3 but i would like to do T4 with some clen for 5 weeks.I thought i will start with 50 mcg of T4 and up to 200mcg a day.I will have a shutdown in 5 weeks of t4 use at this dossage,how harsh is this dossage for thyroid?Thanks for the answers and time.