i used to take it on and off for the last 5 years, now i dont take it.
it does give me a lot of streght increase, but i dont like it because i get bloated with water, even on a clean diet,
you can gain muscle but it mostly depends on your diet anyway.
(when i used it and kept my diet the same i gained 7lbs or so in 1-2 weeks, but it was mostly water), to gain muscle you would have to change your diet to(up to 1k clean cals more per day).
This is just my personal experience