i did it after my SD cycle. i would really recommend it, only because it upregulates your glycogen stores. so you'll drop a little bit of fat, but that huge pump feeling you had throughout your SD cycle with all those carbs will deminish a significant amount. it made me feel alittle disappointed. finally on my second SD cycle, i focused more on cortisol control with my pct then did clen after pct was over. I felt no rebound effects on cortisol or water retention during my pct (added a cortisol blocker with my SERM) and i loved it, i stayed lean yet pumped... then i ran a clen cycle and still felt good muscle pumps while killing my fat cells.