Naltrexone is an opioid antagonist, meaning that it blocks your opioid receptors and basically prevents opioids from having an effect. Naltrexone and naloxone

Naltrexone is an opioid antagonist, meaning that it blocks your opioid receptors and basically prevents opioids from having an effect. Naltrexone and naloxone (another opioid antagonist) are used in treating opiate addictions. Not an expert, but my understanding is that these receptors (and naturally occurring opioids) play a role in the reward pathways in the brain, so it's possible that naltrexone and other opioid antagonists could be effective for other types of addiction or compulsive behaviors.