Naltrexone: What It Is and How It Helps

Naltrexone is a medicine that blocks opioid receptors in the brain. That makes alcohol and opioid highs less rewarding, so many people use it to reduce cravings and help stay sober. It’s used for alcohol use disorder and to prevent opioid relapse. There’s also a low-dose trend for pain and inflammation, but that’s a separate topic and not proven the same way.

The drug comes in two common forms: a daily oral tablet and a monthly injection called Vivitrol. The tablet is simple—take it every day as prescribed. The injection lasts about 30 days and removes the need to remember a daily pill. Each option has pros and cons: tablets are flexible for dose changes; injections remove daily adherence worries but require a clinic visit.

How it’s used and what to expect

Doctors usually start naltrexone after the body is free of opioids. If you still have opioids on board, naltrexone can trigger sudden withdrawal. That’s uncomfortable and can be dangerous. For alcohol, people can start once they stop drinking and after a medical check. Expect cravings to drop and alcohol to feel less satisfying over a few days to weeks.

Common side effects include nausea, headache, fatigue, and sleep problems. Most are mild and fade in a week or two. A small number of people get liver enzyme changes, so doctors often check liver tests before starting and during treatment. If you notice new stomach pain, dark urine, or yellowing skin, tell your provider right away.

Safety, interactions, and practical tips

Don’t use naltrexone if you’re actively taking opioids or using opioid-containing pain medicine. Also avoid it if you have severe liver disease. If you use opioid pain relief for surgery or injury, you’ll need discussion with your doctor so pain can be managed safely. Mixing naltrexone with other drugs doesn’t usually cause direct interactions, but every extra medicine raises the need for careful monitoring.

Thinking about starting naltrexone? Have a clear plan: confirm you’re opioid-free, get baseline liver tests, and choose the form that fits your life. If remembering pills is hard, a monthly injection could help. Stay honest with your prescriber about drug use and pain needs—this keeps treatment safe and effective.

Finally, keep expectations realistic. Naltrexone reduces the urge and the reward, but it isn’t a cure. Combining medication with counseling, support groups, or therapy gives the best chance of lasting change. If you have questions about cost, delivery, or how to get Vivitrol shots, ask your clinic or pharmacist—many places offer help with access and coverage.