The best way to protect your liver is to not use high doses of orals for an extended period. Oils are the way to go for most of your cycle. Orals should only be used for short periods and in controlled doses. Remember that there is nothing that will make you bullet proof. If you use dangerous amounts of orals, there is more likely to be problems. So that being said, the first thing I would look into is NAC. NAC is very cheap. There is a ton of great info out there and I suggest you do a quick google search to see for yourself. It really is a no brainer at the price. I use this at 1500mg ED on and off cycle for Liver and kidney health. And there is a newer supp on the market that is causing quite a stir. Tudca. This one is a little more expensive, but it will help protect the liver as well as benefit your health in a number of other ways at 500mg ED. These are my main supps. I also will use milk thistle a 1000mg ED starting several weeks before I begin an oral, then running it through the oral steroid run and several weeks beyond. I also take it for longer periods while not on orals too, but I do not use milk thistle year round. 

For anyone interested working 1 on 1, I offer my coaching services here at Naps through the Next Level Nutrition page. Feel free to message me today and get started on a plan for the new year!