To make it easier to understand why injectable steroids have less side effect compared to oral ones, it should be mentioned that how oral steroids act on the body. As it is known anabolic steroids are taken in two forms. Orally or by injection. When oral steroids are taken they need to pass through digestive system of the body and the kidney to get into the bloodstream. While they are passing through they are tend to cause serious side effects. At this point, injectable steroids promotes such beneficial effects. Injectable ones do not need to pass through digestive system. In other words they are able to get into bloodstream directly. Hence, there are less likely to cause such side effects compared to oral steroids.