They both have their benefits and depending on what you take, you can make incredible gains with each. A natural guy can put on serious weight and strength with ghrp6, for example. A person can put on serious strength and weight with testosterone. It all depends on your goals and what you are willing to take. Side effects vary with various peptides, just as they do with various anabolic steroids. You have to be more specific in your question to know specific side effects per specific compound.