Naltrexone: Uses, dosing, side effects, and what to expect

Naltrexone is a medication that blocks opioid receptors. Doctors use it mainly to help people stop drinking alcohol and to prevent relapse to opioid use. You might also hear about low-dose naltrexone (LDN) used off-label for chronic pain and some autoimmune conditions. This page gives clear, practical info so you know what naltrexone does and whether it might fit your plan.

How naltrexone works

Naltrexone sits on opioid receptors in the brain without activating them. That prevents other opioids from producing their usual high. For alcohol use, naltrexone can reduce cravings and the reward from drinking. It doesn’t sedate you or cause a high on its own. If you have recent opioid use, starting naltrexone can trigger withdrawal, so timing matters.

Typical treatment for alcohol dependence uses 50 mg once daily. For opioid dependence, a healthcare team will decide between oral doses or an extended-release monthly injection. Low-dose naltrexone usually ranges from 1.5 mg to 4.5 mg at night, but evidence for LDN is limited and still evolving. Always follow a prescriber's directions.

What to watch for

Common side effects are nausea, headache, dizziness, and fatigue. Most people notice these for a short time and they fade. Serious problems are rare, but naltrexone can harm the liver at high doses or in people with active liver disease. Your doctor may check liver enzymes before and during treatment.

Naltrexone blocks opioid pain relief. If you need emergency surgery or strong pain meds, treatments that usually work may not be effective. Carry a medical alert note or tell emergency staff you take naltrexone. Also, using naltrexone while still dependent on opioids can cause sudden withdrawal—this is uncomfortable and sometimes dangerous.

Interactions include opioid medications and some strong painkillers. Combining alcohol or other drugs with naltrexone does not increase effectiveness. Herbal supplements and over-the-counter drugs rarely interact, but always list everything you take for your prescriber.

Thinking about getting naltrexone online? Use a licensed telehealth service or a pharmacy that requires a prescription. Avoid sites that sell without a prescription or don’t show contact details. Safety checks like verified pharmacy seals and clear return policies matter.

Questions to ask your prescriber: Is naltrexone right for my type of dependence? Do I need liver tests first? What should I do if I miss a dose? Is low-dose naltrexone an option for my symptoms? A short, honest chat with your clinician clears up whether this drug fits your goals.

Naltrexone can help, but it isn’t a cure by itself. Combining medication with counseling, support groups, and practical plans for triggers gives the best shot at lasting change. If you want links to guides and safe buying tips on this site, check the related posts tagged with naltrexone for more practical reads.

Start by talking openly with your doctor about goals, other health problems, and medications. Expect follow-up visits in early weeks to adjust dose or check labs. Small changes early make treatment safer and more effective.