Naltrexone for Alcohol: How It Works, Dosage & Can You Drink on It?

Naltrexone for alcohol is an FDA-approved medication that lowers cravings and makes drinking feel less rewarding. It comes as a 50 mg daily pill or Vivitrol®, a 380 mg shot given every 4 weeks. Drinking on naltrexone doesn't cause a dangerous reaction, but treatment works best if you stop drinking before you start.

MATClinics gives Vivitrol injections every 4 weeks at eight Maryland locations. Ask whether the monthly shot is right for you.

How Does Naltrexone Reduce Alcohol Cravings?

Naltrexone blocks opioid receptors in the brain. These receptors are part of the reward system that makes drinking feel good. When they're blocked, alcohol delivers less of a "lift," and the pull toward the next drink tends to weaken.

The National Institute on Alcohol Abuse and Alcoholism (NIAAA) describes naltrexone as blocking "the receptors in the brain that are involved in craving alcohol or the rewarding effects of drinking." The FDA label is more cautious. It says the exact way naltrexone works in alcohol dependence is "not understood," though research points to the body's natural opioid system.

Naltrexone is not an opioid, and it is not addictive. It also does not make you sick when you drink, which sets it apart from disulfiram (Antabuse).

What Is the Typical Naltrexone Dosage for Alcohol?

Naltrexone for alcohol use disorder comes in two forms. Your clinician chooses the form and dose based on your health, goals and treatment history.

Oral Naltrexone Tablets

The FDA label recommends 50 mg once daily for most patients. In the label's alcohol studies, patients took 50 mg once a day for 12 weeks.

Vivitrol (Monthly Injection)

Vivitrol is extended-release naltrexone. The label dose is 380 mg, injected deep into the buttock muscle by a healthcare provider every 4 weeks or once a month. Drug levels begin to slowly drop about 14 days after a shot but stay measurable for more than a month.

Because one shot covers a month, Vivitrol removes the daily decision to take a pill. That can help people who find it hard to stay consistent.

Can You Drink on Naltrexone?

You can, and it won't cause the dangerous reaction that Antabuse does. The FDA label states that naltrexone "does not cause a disulfiram-like reaction" when combined with alcohol. You won't get the flushing, vomiting and racing heart that Antabuse causes.

That doesn't mean alcohol becomes safe. Naltrexone does not keep you from getting drunk, so alcohol still affects your judgment, coordination and driving. Heavy drinking also keeps stressing your liver while you're on the medication.

Why Stopping First Usually Works Better

The research behind naltrexone points to better results when people stop drinking before they start. A guide from the Substance Abuse and Mental Health Services Administration (SAMHSA) and NIAAA lists naltrexone for people who can stop drinking as outpatients before treatment begins.

The Vivitrol label is even clearer. People should not be actively drinking at the first injection. In the main 24-week Vivitrol trial, the benefit showed up in the small group who had stopped drinking before treatment. The label says the same effect was not evident in those still drinking at the start.

If you're still drinking every day, tell your clinician. Depending on how much you drink, stopping safely may need medical support first.

How Long Does It Take Naltrexone to Work for Alcohol?

There's no single answer, and studies measure results over weeks and months rather than days. The oral naltrexone studies in the FDA label ran for 12 weeks. The main Vivitrol trial ran for 24 weeks.

Responses vary from person to person. Keep track of your cravings and drinking days so you and your clinician can judge progress together.

Duration matters too. The SAMHSA and NIAAA guide says treatment with alcohol use disorder medications "should continue for at least 6 months to 1 year." It also notes that the best length of treatment is not known.

How Effective Is Naltrexone for Alcohol Use Disorder?

Naltrexone is one of the best-studied medications for alcohol use disorder. Three sources show what it can do.

• Large review of trials: A 2023 review in JAMA pooled 118 clinical trials with 20,976 participants. For oral naltrexone at 50 mg a day, about 1 in every 18 people treated avoided a return to any drinking because of the medication. About 1 in 11 avoided a return to heavy drinking.
• FDA label study: In one 12-week trial of 104 people, 31% of those on naltrexone relapsed to heavy drinking compared with 60% on placebo (a dummy pill).
• Monthly injection: The same 2023 JAMA review found injectable naltrexone was linked to about 5 fewer drinking days per month.

Those numbers mean naltrexone helps many people but not everyone. It works best as one part of a full treatment plan.

Despite this evidence, few people get it. A National Institutes of Health (NIH) analysis of 2019 survey data found that only 1.6% of the 14.1 million U.S. adults with alcohol use disorder used an approved medication for it.

Oral Naltrexone vs. Vivitrol: Which Is Right for You?

Both forms contain the same medicine. The main differences are how often you take it and what side effects you notice.

Daily Pill

• Taken once a day at home
• Can be stopped quickly if side effects become a problem
• Only works on days you take it, so missed doses matter
• Nausea was the most common side effect in the label's alcohol studies, at about 10%

Monthly Vivitrol Shot

• Given by a provider every 4 weeks
• Steady coverage, with no daily pills to remember
• Injection site reactions were reported in 69% of people on Vivitrol 380 mg vs. 50% on placebo in the label's alcohol trials
• Nausea was reported in 33%, compared with 11% on placebo

For a full look at what to expect from each form, read our guide to naltrexone and Vivitrol side effects. It also covers liver monitoring and how long side effects tend to last.

Important Safety Notes for Both Forms

Naltrexone blocks opioids, including prescription pain medicine. People need to be opioid-free for at least 7 to 10 days before starting, or they can go into sudden withdrawal. Tell your provider if you take any opioid, including for pain.

The labels also warn about overdose risk after naltrexone wears off. Someone who uses opioids after stopping naltrexone, after a missed dose or near the end of a Vivitrol month can overdose on amounts they once tolerated. Your clinician will also check your liver before starting and watch for mood changes during treatment. 

Why Pair Naltrexone With Counseling?

Naltrexone can quiet cravings, but it doesn't change the habits, stress and situations tied to drinking. Counseling works on those.

Most of the research on naltrexone already includes counseling. Of the 118 trials in the 2023 JAMA review, 100 combined medication with some form of non-medication treatment, according to a Boston University summary of the study.

At MATClinics, substance use counseling includes individual sessions, group therapy and approaches such as cognitive behavioral therapy (CBT) and motivational interviewing. Counseling and medication can start at the same time.

Starting Naltrexone Treatment at MATClinics

MATClinics provides outpatient alcohol use disorder treatment across Maryland, including on-site Vivitrol injections every 4 weeks. Your first visit covers your drinking, health history and any opioid use, so your clinician can tell you which medication fits and whether you need help stopping drinking safely first.

MATClinics accepts Maryland Medicaid, Medicare Part B and CareFirst plans. Request your first appointment online, or call 410-220-0720 if you have questions before booking. If you live outside Maryland, FindTreatment.gov, run by SAMHSA, lists licensed treatment providers near you.

Frequently Asked Questions

What Happens If You Drink Alcohol on Naltrexone?

Nothing dangerous happens from the combination itself, because naltrexone does not cause a disulfiram-like reaction. The medication is meant to make drinking feel less rewarding. You can still become intoxicated, so the usual risks of alcohol remain.

What Is the Usual Dose of Naltrexone for Alcohol?

The FDA label recommends 50 mg once daily for most patients taking the pill. Vivitrol is given as a 380 mg injection every 4 weeks. Your clinician decides which form and dose are right for you.

How Long Should You Take Naltrexone for Alcohol?

A SAMHSA and NIAAA guide recommends continuing alcohol use disorder medication for at least 6 months to 1 year. The ideal length varies from person to person. Talk with your clinician before stopping.

Is Naltrexone Better Than Antabuse?

They work differently. Naltrexone reduces cravings and the reward from drinking, while Antabuse makes you sick if you drink. Our comparison of medications for alcohol use disorder explains which situations suit each one.

Can You Take Naltrexone If You Take Opioid Pain Medicine?

No, not at the same time. Naltrexone blocks opioid pain relievers and can trigger sudden withdrawal in people who use opioids. You need to be opioid-free for at least 7 to 10 days before starting.

Is Naltrexone Addictive?

No. Naltrexone is not an opioid and does not produce a high. NIAAA describes alcohol use disorder medications, including naltrexone, as non-addictive.

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