Winny is a mild anabolic. It is 17aa, but isn't extremely harsh on the liver as long as u don't stay on too long.
It doesn't aromatize so water retention and gyno is not a problem, some people experience accelerated hairloss, but that depends on predisposition. Use clomid post to recover natural test. As for gains using it alone will make u hard, with moderate strength gains and mild mass gains.