I think someone i hang out with is using drugs. What kind of drug?!

I think someone i hang out with is using drugs. What kind of drug?

i dont know what would cause a persons lips to go almost blue.

A drug which causes lips to go blue is a drug which is causing the user a breathing & blood circulation problem. Drugs can cause the heart to go so slowly that it finally stops without any warning.
If he is sniffing drugs up his nostrils, the irritation of this will cause him to continually sniff. he will also have mood turns and sudden impatience and quite honestly, get really pathetic with some things he says and does.
Look at his eyeballs - depending on how drugs alter his temperament, you can usually notice that they are either over-dreamy or a bit manic.
Also - ask him what he thinks of drugs. All users condone the use of them, and all non-users have no time for them.
Look in his wallet and see if there is a small folded piece of paper or a short straw.
Otherwise, watch him when you go out to a disco and if he appears drunk before drinking anything.
If he has been on drugs for any length of time he will begin to find it difficult to get a proper erection and keep it going.