Honestly, it's a crap shoot. T2 seems to be suppressible and you will hear various things. You won't see much research on it, other than it showing it is suppressible with 3,5 being less so. IMO the results are non-existent and not even worth the risk - but I don't even really get a ton from actual T3 so I may not be the best judge. Based on my experience, I had high hopes for this and had used it off and on from 2000 - 2015 before I really just gave in and accepted it was worthless. I even ran it at 1200 mcg/day (do not do this, it's stupid, I'm stupid) and that pretty much convinced me.