Why do i still crave heroin so much even when im on subutex?

Not magic: Subutex is a great tool but not always enough. Some people with high heroin tolerance dont get complete relief. Because subutex only partially stimulates the opiate receptor there is a limit to what it can do. Above 24 mg no good evidence of increase benefit and not recommended. Talk to your doctor. If relapse is concern Methadone maybe more effective. But counseling and meetings help as well.

Lots of reasons: You might not be on enough Buprenorphine and you need to share your craving with your doctor or counselor. If you don't have a counselor, you need one. If you aren't attending any self-help groups, and haven't been given counseling on how to deal with craving, how to occupy your mind and body in other ways, you are not getting enough treatment. Get more.