Home / Teen / Drugs and Alcohol Heroin What is heroin? Heroin is a drug that is made from a poppy plant and is very dangerous to use. What should I do if I need help? Contact us to learn more about the dangers of heroin and how we can help. If you feel like you need immediate help, call the Centerstone Crisis Line nearest you. How does heroin affect me? Once someone becomes addicted to heroin, it is very hard to stop using it. This is especially dangerous because, if someone uses too much heroin, they can “overdose.” An overdose is what it’s called when someone uses too much of a drug and it harms them. Heroin overdoses can cause vomiting, lack of oxygen to the brain, and even death.