I went with this same stack (1-t+Epistane) for 6 weeks and LOVED it. +13lbs, arms went from 15.5 to 16.3. I took them concurrently and noticed the majority of gains around week 3-4. By week 6 gains had definitely slowed a lot, and sides were starting to kick in more. Libido wise i didn't really notice anything negative until week 5. I would probably recommend a cycle of 5 weeks to ensure you get the most out of it. 6 weeks probably isn't all that bad either, though I certainly wouldn't advise running much beyond that.