Works great, but only if you are already dieting. I.e. eating regular while taking it is just a waste and unhealthy. The down side is a lot of muscle and strength losses.
IMHO, it's best use is after you've started a strict diet and get to that point where your metabolism vastly slows down to compensate for the low caloric intake. Take it then, and that's where you will really see it work.
Just my opinion, but please do lots of research if you don't have the info...... T3 and CLEN are two quite dangerous drugs out there...........................
T3 must be ramped up and ramped off of very slowly to make sure you regain your body's normal thyroid production though....CLEN is also dangerous if you don't know what your doing....start by taking 1 tab 20mg and increase 1 tab each day until you cant take the side effects--headaches, joint pain, shaking, insomnia, etc....also, its half life is somewhat long so a 2 day on and 2 day off should limit sides too.....
You can even do a quick search in these forums and you will find LOADS of Great Info on everything, not just T3 and CLEN....Also, there are some extremely educated bro's in here that give us lots of their time and are very helpful......
Good Luck---oh, and to answer your question, I have only heard great positive things for hardening and fat loss using CLEN/T3 together.......and if you have loads of $$$, throw in some HGH with CLEN/T3 and you have my favorite cycle of all time...hahahha
It works great, but you also run the risk of possibly messing up your normal thyroid production for the rest of your life... Chances are that won't happen, but do you want to risk it? I would stick with ECA/ Clen...