I ran t-3 with clen for a long cycle, around 4 months preparing for my show. I started at 25mcg of t-3 and moved my way up each week stopping at 100mcg ed. Clen started at 60mcg and ran it up to 100mcg taken while also taking keto and benadryl as much as I could.
The one thing I noticed more than anything was that I was getting super lean without any cardio. Normally I have to do alot of cardio to get my body fat down, but as I began the t-3 I was in for a big surprise. I still did cardio but half as much as I normally do and I was much leaner on t-3. It was pretty incredible being able to get as lean as I did with minimal cardio. One thing I did do while I was on t-3 was to really monitor my strength in the gym. I made sure my strength stayed the same week to week. I feel I lost a little bit of muscle, but not that much, and it was well worth it in regards to the amount of fat I lost. From my experience I think if you keep on Test and keep protein and aminos really high through out you will be fine. I also would really manipulate my diet to hold as much muscle as I could. But it dones differ for each individual, but I will never be without t-3 again when preparing for a show, I was in my best shape ever. If you do it right there should only be a little muscle loss.