If it hasn't been cut with anything (which you can't assure because of it's illegality), any C-A grade has been proven to be scientifically safer than both alcohol and cigarettes. Don't listen to the fools who tell you that every drug is bad, I bet you most of them have had coffee which contains caffeine.
That said, make sure to constantly sip on water so that you don't dehydrate. Don't take more than one for your first time!