You could take supplements even if you dont workout. You could take protein shakes and meal replacements even if you're not going to gym... Your friend need to first figure out what he needs to accomplish and only then will he be able to know what kind of supplement and food will he need. Supplements are needed only when you cant eat certain amount of calories throughout the day. If your friend want to gain muscle mass and shred fat then maybe... but even then..check the serving label on protein shake and all you'll see is the protein portion being higher than any of the other things. This tells that protein shake is nothing but a quick way of getting protein in ur system. If one is a beginner.. he should try to get his protein dosage through normal food and only if hes unable to do so, he should go for protein shake.. why waste your money on such things so soon?..when you're still a beginner and you havent hit plateue ? Supplements are not going to be of any help to anyone if your lifting technique is wrong or if you havent been eating right.
Again, there isnt anything wrong with your friend taking supplement.. but make him eat the real healthy food containing protien , carbs, and healthy fat...and then once he knows much about the way his body works.. he can make some adjustments into his diet and maybe throw in a protein shake in his diet.
Thank you everyone