Well, if you don't want to do something, don't do it. Teenagers just like adults have the freedom to resist their peers' suggestions. If your friend forces you to take a drug at gunpoint, sure, that's wrong. But if he just tells you it'll make you feel good and you voluntarily go along with him under your own free will, I don't see what's wrong with that. Most peer pressure isn't done by force since people generally don't hang around assholes who force them to do shit they don't want to do.