It depends on the quality of meat that you can serve it or not. In case you are using fresh meat as a steak then you can blindly put your interest in it. And it is completely safe to eat medium-rare steak even though you will get the original and delicious taste from it if cooked properly. Most importantly, the internal medium rare temp should reach 145 degrees. Cooking the steak at this temp will provide you with a great piece of steak.