If you did have "liver failure" then I highly doubt SD was the only factor involved. Did you have an underlying health issue involving your liver or did you run 200mg of SD everyday for 48 weeks?
Yes, precautions are to be taken by using liver supplements. A 4 week run at 30mg would not give any lasting damage unless you are also drinking and using prescription medications that don't mix well at the sam time.
These are for healthy individuals. If you are not healthy, don't mess with this stuff.
I tried it, hated it. Raised my Bp, retained buttload of water, just wasnt worth it risk vs reward. Superdrol is still avaialble over the counter just have to know where to go...plus it goes by a new name now...do yourself a favor and grab some Dbol and Test instead...