Someone has already said this I think
But be truthful with your brother tell him that it does him no good and will never do him any good at all.....
Say you have never found any reason to do drugs in your life and you are doing good in life.... Make him see the positive side of not doing them and also give him a small insight into what life could be like if he got heavily into drugs!!
I know its very easy for all of us to sit here typing away telling you what to say but in reality its a lot harder than we can imagine!
My cousins friends were trying to get him to smoke marijuana and he told my uncle about it.... My uncle said ok if you wanna try you will do it infront of me! Just so he would be there if anything happened and my little cousin tried it ( this was about 1 year ago) and to this day he has never touched the stuff again!!!
I am not saying you should let your brother try it but try and make him understand that it isn't the best or smartest thing on earth and also tell him he will have better things to spend his $$$ on!!!
Just my

Hope it helps Cheshire
ps thanx for the e-mail back about the T shirt for Angie!
