I don't give a shit what others put into their bodies as long they're not harming people. The most dangerous thing about drug use is how staggeringly boring they make you. I've no interest in being around druggists any more.
And that is where actually the problem is since many crimes are omitted under the influence of drugs. I am also in favor of not constricting anyone with whatever they want to do with their lives...if they want to commit suicide then that is fine with me as long as they don't harm others in the process.
But the BIG QUESTION: Are we not really harming/hurting (physical and emotional aspects) the people around us when we are not anymore normal and we are already harming ourselves in the process? Do you think our loved ones would be happy seeing us wasted? Be honest.