Drugs may also be used to help treat self-injury. It is thought that self-injury can release chemical endorphins into the brain. Over time, these chemicals can become addictive. There are some drugs that can help with this addiction, but they have not been proven to help people who self-injure. Naltrexone and naloxone are two drugs being researched for this kind of treatment. Research involving endorphins has been mostly done with animals. It is unclear if their brain chemistry changes the outcome of the research.