Never used it, but just like when your dieting, and cals are below maintenance, some muscle loss is inevitable. As long as protein is high, you can keep it to a minimum. I had a friend who had a problem with lethargy when on, so I think, a stimulant of some sort like ECA is a must. I would keep it fairly low, maybe 75mcg tops, the first time around, to see how you react to it. Im sure you know about the ramping up and down. To all the people who are going to say it, NO T3 WILL NOT PERMANENTLY SHUT DOWN YOUR THRYOID.
Sorry.