Stanozolol appears to offer less hepatic stress than an equivalent dose of Dianabol (methandrostenolone). Studies giving 12mg of stanozolol per day for 27 weeks failed to demonstrate clinically-significant changes in markers of liver function, including serum aspartate amino-transferase, alanine amino-transferase, gamma-glutamyltransferase, bilirubin, and alkaline phosphatase. 621 Relative hepatotoxicity increases as the dosage escalates, so hepatic dysfunction should still be a concern. In rare instances, high doses (alone or in combination with other steroids) have been implicated in cases of serious life-threatening hepatotoxicity in bodybuilders. Injectable stanozolol has also been implicated in severe hepatotoxicity in an otherwise healthy bodybuilder, 622 and should not be used as an alternative medication when liver toxicity precludes oral stanozolol use.
That depends a lot on what your goals are. Typically, it is considered important for the sake of your health not to take the drug continuously. You will want some time away from the drug in order to give your body the time it needs to recover. This can be invaluable time for your liver to flush out toxins and return to a healthier state before you begin again. Consider a 10-week cycle of the drug. For the last two weeks, gradually reduce the dosage to help get your body off of it before stopping completely. This will help to reduce issues regarding side effects.