If you have healthy liver it can take quite a beating and recover nicely given proper support. From my personal experience I ran Winny for 4 months at 50mg/D (along with Test and other crap) and according to blood test I took last week it is working just fine. Of course your mileage may vary but the point is liver quite a fighter, if you have a healthy one it can withstand some discomfort.
One thing to note, Winny is hard on joints. So take supps for that and don't push too hard. Gear can make your muscles stronger but joints need time to catch up with the meat.