# Naltrexone for Alcohol: How It Works and What to Expect

> Naltrexone for alcohol: how it eases cravings and heavy drinking, pill vs monthly shot, side effects, and why it does not treat alcohol withdrawal.

URL: https://foundationmedicalgroup.org/naltrexone-for-alcohol/
Published: 2026-09-29
Updated: 2026-09-29

Naltrexone is one of three FDA-approved medicines for alcohol use disorder (AUD). It blocks opioid receptors in the brain that make drinking feel rewarding, which can reduce alcohol cravings and help prevent a return to drinking heavily. It comes as a daily pill or a monthly injection. It isn’t addictive. But (and this part surprises people) it doesn’t treat alcohol withdrawal.
This page gives general information from government health sources. Foundation Medical Group does not treat AUD, so please use it to prepare questions for your own doctor. If you’re worried about someone you love, the same goes for you. That’s a heavy thing to carry, and reading up quietly is a reasonable place to start.
What Is Naltrexone for Alcohol Use Disorder? Naltrexone is a prescription medication in a group of drugs called opioid antagonists. MedlinePlus calls it an opiate antagonist. Sounds alarming, right? It isn’t. SAMHSA, the Substance Abuse and Mental Health Services Administration, is clear that it isn’t an opioid and isn’t addictive.
Doctors use it for two conditions. The pill is used for AUD, which some people still call alcohol dependence. According to SAMHSA, the monthly injection is approved for both AUD and opioid use disorder (OUD).
The medicine isn’t new. NIAAA, the national institute for alcohol research, notes that the FDA approved the pill in 1994 under the brand name Revia, and the extended-release injection, sold as Vivitrol, in 2006. MedlinePlus adds that the ReVia brand is no longer on the market, but generic versions may be available.
It’s not meant to work alone. MedlinePlus says naltrexone is used together with counseling and social support, and SAMHSA describes it as part of a full treatment plan that includes counseling. So naltrexone use works best as one part of a bigger plan, with real support around you.
SAMHSA also says it’s not recommended for anyone younger than 18. If you’re a parent reading for a teenager, talk with your child’s doctor.
Like all medications, it carries risks as well as benefits. We’ll get to those further down.
How Does Naltrexone Reduce Alcohol Cravings and Heavy Drinking? When you drink, your brain releases its own feel-good chemicals. Those chemicals act on opioid receptors, which is part of why drinking can feel rewarding. Naltrexone blocks those receptors. Simple idea, really. With the reward turned down, drinking can feel less pleasant, and cravings may ease.
NIAAA says the medicine blocks receptors involved in the pleasant sensations of drinking and can reduce craving. SAMHSA explains that it binds to endorphin receptors and blocks the effects and feelings of alcohol. It can also reduce cravings and the amount of alcohol consumed, SAMHSA says, and it can help people who’ve stopped drinking stay sober.
There’s a catch, though. MedlinePlus says it helps only as long as you keep taking it. A bit deflating, maybe? Naltrexone therapy isn’t a cure that keeps working after you stop.
What counts as heavy drinking? NIAAA uses these numbers:
For women: 4 or more drinks on any day, or 8 or more per week For men: 5 or more drinks on any day, or 15 or more per week Cutting back counts, too. Really. Lower alcohol intake is a real goal, not only stopping completely, and if an all-or-nothing mindset has kept you from even asking, that’s worth knowing. Reducing your alcohol consumption can still be a meaningful change, including for people living with alcohol dependence. Your doctor can help you set a goal that fits your life.
Oral Naltrexone vs Injectable Naltrexone at a Glance The medicine comes in two forms: a pill, called oral naltrexone, and injectable naltrexone, a shot. Here’s how they compare, based on SAMHSA, NIAAA and MedlinePlus.
Pill Injection (extended release naltrexone) How often Once a day Every 4 weeks (once a month) Who gives it Taken at home or under supervision at a clinic A practitioner gives the shot FDA approval for alcohol 1994 2006 Approved for OUD No (only the injection is approved for OUD) Yes Brand names ReVia (no longer on the market; generics may be available) Vivitrol Key form-specific risk Missing daily doses Injection site reactions The pill means daily dosing, so missed doses are the main risk. The shot is given once a month by a practitioner. SAMHSA notes that the injection can cause serious injection site reactions, so tell your prescriber about any problem where you got the shot.
This table shows the schedule only. Your prescriber picks the form and the naltrexone dosage that fits you. Dosing is a medical decision, not something to work out alone.
You may also see “low dose naltrexone” online. The sources used here don’t describe it for alcohol, so we can’t say whether it helps. Ask a doctor rather than adjusting your own doses.
Can You Start Naltrexone While Still Drinking Alcohol? Short answer? It depends on who you ask, because the sources don’t all agree. Here’s each view.
NIAAA, in its guide for clinicians, says naltrexone can be started while a patient is still drinking. SAMHSA says that when starting naltrexone treatment for AUD, patients must not be physically dependent on alcohol. Practitioners typically wait until after alcohol detox to avoid strong nausea and vomiting. MedlinePlus describes it for people who have stopped drinking alcohol. So let your doctor decide, based on your health and how much you drink. If you have signs of alcohol dependence or drink heavily every day, talk with a doctor about safe withdrawal care first. Mixed advice can be frustrating when you just want a clear answer. But that’s exactly why the call belongs to a doctor who knows your history.
You may also read about targeted dosing, which means taking a pill only before a drinking day. The sources used here describe only a daily pill or a monthly shot, so ask your doctor and don’t change your schedule on your own.
There’s one firm rule about opioids: you can’t start this medicine with opioids in your system. Be open with your doctor about all substance use. MedlinePlus says to tell your doctor about any opioid used in the last 7 to 10 days, including some pain, cough or diarrhea medicines, methadone or buprenorphine. SAMHSA says to wait at least 7 days after short-acting opioids and 10 to 14 days after long-acting ones, or sudden opioid withdrawal can follow. Our page on precipitated withdrawal explains how this happens with opioids.
Does Naltrexone Help With Alcohol Withdrawal? The short answer is no. MedlinePlus says naltrexone won’t prevent or relieve withdrawal symptoms. It may also cause or worsen withdrawal in people who use opioids, so the opioid rule above matters.
Withdrawal from alcohol can be serious. NIAAA lists symptoms such as trouble sleeping, shakiness, restlessness, nausea, sweating, a racing heart and seizure. NIAAA also notes that about half of people with AUD have some withdrawal symptoms when they stop drinking, and a small proportion need intensive inpatient care. That’s a scary list to read. Thankfully, you don’t have to plan for it alone.
So if you’ve been drinking a lot for a long time, talk to a doctor before you stop. They can check whether you need medical withdrawal care. If someone has a seizure, becomes confused or has any other emergency, call 911.
Please know what Foundation Medical Group does not offer. We do not provide detox, alcohol rehab, IOP, PHP, residential care or 24/7 supervision, and we do not treat alcohol addiction. Withdrawal care must come from another medical provider, such as your own doctor or a hospital.
Alcohol abuse and other substance use problems can feel isolating. Saying it out loud tends to be the hard part. But asking a doctor for help with substance use is a safe first step.
How Effective Is Naltrexone Treatment for Alcohol Use Disorder? Naltrexone won’t make the problem vanish overnight. Still, it’s an evidence-based option. NIAAA says the three approved medications can help prevent a return to drinking heavily and can promote abstinence. Medications and behavioral treatment are about equally effective, NIAAA adds, and the two can be combined.
So how big is the effect, really? A 2023 review of 118 clinical trials in JAMA found that oral naltrexone had a number needed to treat of 18 to prevent 1 person from returning to any drinking, compared with placebo. For a return to heavy drinking, it was 11. Put simply, for every 11 people who take the pill, about 1 more person avoids going back to heavy drinking than with a dummy pill. That may sound small. For the person who stays off heavy drinking, it isn’t.
What does progress look like? It can mean fewer heavy drinking days or less binge drinking, not only a perfect record. Any steady drop in alcohol use matters. A rough week doesn’t wipe out the good ones.
NIAAA also stresses that what helps one person may do little for the next. If one medicine doesn’t help, trying another is common in addiction treatment, and it doesn’t mean you failed.
For a lot of people, mutual support is part of the plan too. NIAAA mentions groups such as Alcoholics Anonymous and secular options such as SMART Recovery, alongside medical care for a substance use disorder.
Here’s the part that’s hard to square: these medicines are rarely used. NIAAA cites a 2021 analysis in which AUD medications were prescribed to only 1.6% of adults with past-year AUD. And the newer federal numbers? Not much better. According to NIAAA, the 2024 National Survey on Drug Use and Health found that 27.9 million people ages 12 and older had AUD in the past year. NIAAA also reports that only 2.5% of people in that age group with past-year AUD, about 697,000 people, received medication for it. Honestly, that’s a strikingly small share for an evidence-based option. Frustrating, too, if you might have benefited and the subject just didn’t come up. If you think medicine could help you, ask your doctor directly. Addiction is a health condition, and substance abuse deserves the same medical care as any other condition.
What Are the Side Effects of Naltrexone? SAMHSA lists these common side effects:
Nausea, vomiting or decreased appetite Sleepiness, headache or dizziness Painful joints or muscle cramps Cold symptoms or trouble sleeping Toothache Tell your prescriber if any of these bother you or don’t go away.
Some side effects are serious. Call your doctor or get emergency care if you notice signs of liver damage, such as stomach pain that lasts more than a few days, dark urine, yellow eyes or skin, or unusual tiredness. The same goes for a serious allergic reaction, a severe injection site reaction, depressed mood or thoughts of hurting yourself. Before you start this medication, tell your doctor if you have liver or kidney disease.
This next part is a sobering opioid danger, and it’s easy to overlook. MedlinePlus warns that taking higher doses of opioid medication or street opioids to get past the block can cause serious injury, coma or death. SAMHSA adds that after you stop naltrexone, your tolerance is lower, so even an old or lower opioid dose can be life-threatening. MedlinePlus suggests carrying medical identification. If you live with opioid dependence or opioid addiction, talk with a doctor before starting. (For people who get Vivitrol for opioid use disorder at our American Fork or Dallas clinics, our clinicians go over this risk at the intake visit.)
You can report serious side effects to the FDA MedWatch program at 1-800-FDA-1088, as SAMHSA notes.
Naltrexone vs Naloxone and Disulfiram: What Is the Difference? These names are easy to mix up (they even sound alike), but they do very different jobs.
Naltrexone vs naloxone. Naloxone is an opioid overdose reversal medicine used in emergencies. SAMHSA lists naloxone and nalmefene as opioid overdose reversal medications. Naltrexone is a daily or monthly medicine for AUD or opioid addiction. Both work as an opioid antagonist, but one is for an emergency and the other is for ongoing treatment. Don’t swap one for the other.
Naltrexone vs disulfiram. NIAAA explains that disulfiram causes flushing, nausea and other unpleasant effects if a person drinks. Put another way, it makes people feel sick when they drink. Naltrexone doesn’t work that way, and it doesn’t make you sick when you drink. It works by turning down the reward and the craving.
Acamprosate. This is the third approved medicine for AUD. NIAAA says it’s started after withdrawal, once a person has stopped drinking.
Each of these medicines has its place. Your doctor can help match the medicine to your goals and your history of substance abuse.
Does Medicaid Cover Naltrexone? Coverage depends on your plan and your state. The national sources used here don’t list coverage rules, costs or approval steps, so the surest way to find out is to ask your plan directly. Tedious, we know.
Call the number on the back of your Medicaid or insurance card and ask:
Is the naltrexone pill covered? Is the monthly injection covered? Do I need prior approval before my doctor can prescribe it? Which substance use treatment benefits does my plan include? Each state runs its own Medicaid program, and the names can differ. For example, Virginia’s Medicaid program is called Cardinal Care. Virginia’s Medicaid agency says each managed care plan has its own list of covered medicines, while fee-for-service members use the Virginia Medicaid Preferred Drug List. More than one list, then, depending on how you’re enrolled. So ask your plan about naltrexone by name. If you’re not sure which Medicaid plan you have, your card or your state Medicaid office can tell you.
Your doctor’s office may also be able to help you check whether a prescription medication is covered before you fill it. It’s a dull call to make, sure. Still, it beats a surprise at the pharmacy counter.
Where to Find Help for Alcohol Use, and What FMG Offers for Opioid Use For alcohol use: start with your own primary care provider. Bringing it up can feel awkward. That’s normal, and it’s still worth saying. They can review your drinking, your overall health and whether a medicine like naltrexone fits you. NIAAA also offers a free online tool called the Alcohol Treatment Navigator. The SAMHSA and NIAAA pages in our Sources are good places to learn more about substance use care.
Foundation Medical Group does not treat AUD. We do not offer detox or 24/7 supervision.
For opioid use disorder only: Foundation Medical Group offers medication assisted treatment for OUD in all four of our states, at clinics in Richmond, VA; American Fork, UT; Decatur, GA; and Dallas, TX. See our MAT and Suboxone page for opioid treatment. Vivitrol, the injectable naltrexone, is offered for OUD at only two of them, in Utah and Texas. One practical detail: before the first shot, you need to be opioid-free for 7 to 14 days. The injection visit itself? About 15 minutes.
American Fork, UT: 456 E State Street, Suite 1400, American Fork, UT 84003, on the Wasatch Front. Call (801) 876-5998 (see our Utah page) Dallas, TX: 8390 Lyndon B Johnson Freeway, Suite 500, Dallas, TX 75243, our North Dallas office, right on LBJ Freeway. The number there is (469) 909-1312. Then comes the insurance question (you probably saw that coming). For opioid care in Utah, Medicaid plans to ask about include Health Choice Utah, Healthy U, Molina Healthcare of Utah and SelectHealth Community Care. Call to confirm coverage. In Texas, ask about Texas Medicaid and call to confirm coverage. In Virginia, Medicare is not accepted.
Key Takeaways Naltrexone is one of three FDA-approved medications for alcohol use disorder. It blocks opioid receptors tied to the reward of drinking and can reduce cravings and how much people drink. It comes as a daily pill or a monthly injection, and it is not addictive. It does not treat withdrawal from alcohol, so get medical help before you stop drinking heavily. You must be off opioids before starting. Ask your own doctor whether naltrexone fits you. FAQ What is the usual naltrexone dosage for alcohol? The label schedule is a pill once a day, or an injection every 4 weeks given by a practitioner. Your prescriber chooses the form and sets the dose. Please do not change how much you take, or how often, without talking to your prescriber first.
How long do people take naltrexone for alcohol? SAMHSA says naltrexone treatment for alcohol use disorder lasts three to four months. NIAAA notes that medicines for AUD are generally not needed forever. Your doctor will decide with you how long to continue.
Can you drink alcohol while taking naltrexone? NIAAA says the medicine can be started while a person is still drinking. But it does not make drinking safe. The goal is to drink less or stop, so ask your doctor what is safe for you.
Is naltrexone for alcohol or for opioids? Both. The daily pill is used for alcohol use disorder. SAMHSA says the monthly injection is approved for both AUD and opioid use disorder, so the same medicine can play two roles.
Is low dose naltrexone used for alcohol? The government sources used for this article do not describe this use for alcohol. If you read about it online, ask your doctor before trying anything, and do not cut your doses on your own.
Sources NIAAA (NIH), Recommend Evidence-Based Treatment: Know the Options (Core Resource on Alcohol). NIAAA (NIH), Medications Development Program. MedlinePlus (NIH), Naltrexone. SAMHSA, Naltrexone. NIAAA (NIH), Treatment for Alcohol Problems: Finding and Getting Help. NIAAA (NIH), Alcohol Use Disorder (AUD) in the United States: Age Groups and Demographic Characteristics. NIAAA (NIH), Alcohol Treatment in the United States. JAMA (via PubMed Central, NIH), Pharmacotherapy for Alcohol Use Disorder: A Systematic Review and Meta-Analysis. Virginia Department of Medical Assistance Services, Prescription Drug Formularies.