Definately not as harmful to inject, unless its 17AA like winny. I still take precautions when im not on the orals, things like ALA, high water intake etc.
The injectable do not suffer first pass, therefore they are less harmful to the liver. Depending on which injectable and the dosage you are using they are still VERY prone to stressing the liver. Fina and Equipoise for example are known to be fairly stressful on the liver, where primobolan much less so. So I guess the answer to your question is generally injectable are less stressful on the liver, but it is very dependent on the AS and dosage...
Definately not as harmful to inject, unless its 17AA like winny. I still take precautions when im not on the orals, things like ALA, high water intake etc.