Hello. actually i like to know if some one works out at gym and if they don't use protein powder, it would be harmful for body or not?? thank you

Not harmful: No problem not taking protein powder. The standard for protein is albumin (egg white). You can get all the protein you need by eating normal foods. Of course, if one is trying to build lean body mass (i.e., build muscle), adequate protein is important. But there are lots of other sources of protein besides "protein powder."

Better to not use.: Protein powder is overrated. To gain muscle mass you have to work out for several hours a day for months to years. Protein powder alone will not increase muscle mass. High protein diets have many negative effects. What is your goal? How much do you work out? The best popular information I ever found is in "Weight training for athletes" by Arnold Schwarzenegger, who DOES NOTt recommend it.