1,4BD is processed by the liver where it tunrs into GBL and then GHB. It takes longer to hit you than GHB or GBL but is still fun.
One thing to remember is that you measure your doses carefully and stay in control. Because of the amount of time it takes to start feeling it, many people re-dose before the initial dose has peaked and that can make some people cross/pass out.
And yes, it is bad for the liver, so if you can, use BD for a while, then maybe GBL/GHB and back. Just to switch it up a bit.