Clen is not a steroid so there are no estrogen related side effects with it. You can run clen on its own and get fat loss results. If you want to use it as part of a AAS cycle, many use prop, as it makes you hold less water. Test e also works though. I would also use adex to control estrogen which will help with fat reduction. I'd run your clen at 40mcg for 2 wks, then add 20 mcg every 2 wks, going no higher than 120mcg for a total of no more than 12 wks total