When it really comes down to it, injectable and oral winstrol is basically the same thing. The liver toxicity and bioavailability of the drug are the exact same whether you take the drug orally or inject it. It's not the fact that you take it orally that makes the drug liver toxic, it's the carbon-17-alpha-alkylated chemical structure of the drug that makes it liver toxic.
You need to run a full and proper PCT after any steroid cycle to restore natural testosterone production. I recommend running the perfect PCT protocol. This article explains how to run the protocol and the science behind it -> https://www.evolutionary.org/forums/anabolic-steroids-peds/perfect-pct-simplified!-49252.html