A Friend In Need

My friend started taking oxys a couple years ago and I didn't think anything of it... I thought it was just like smoking weed... harmless... but now he's started shooting up liquid oxy and Im scared. I don't know how to help him. I don't know what to say to him. He's trying to hide it from me, he thinks I don't know and he won't talk to me for weeks at a time because he doesn't want me to see him when he's 'stupid'. Is there a way to help him realise he has a problem and a way to help him without involving anyone else? I don't think he'd take to kindly to me interfering in his life and trying to get him help. What can I do for him? Someone please help me.
Staci,

You have several options in my opinion. None of them would be easy and all involve other people.
1. Intervention
2. Call the family
3. Call the cops

Get your friend some help. Yes... He is embarassed about his addiction and will try to hide it from you. Go ahead... let him hate you now... He will love you later!