Naltrexone and Alcohol: What Happens If You Drink on It

Drinking on naltrexone at a glance

The tablets can be started while drinking; the shot can't

Naltrexone tablets are approved to treat alcohol dependence, usually at one 50 mg tablet a day. In clinical studies, treatment "supported abstinence, prevented relapse and decreased alcohol consumption."¹ Cutting down counts: the American Psychiatric Association's recommendation covers a goal of drinking less as well as stopping.³

Advice on quitting first differs by source:

• NIAAA (US): the tablets can be started while a person is still drinking.¹⁰
• NICE (England): oral naltrexone starts after assisted withdrawal.⁹
• MedlinePlus (US patient drug guide): describes naltrexone as a medicine for people who have stopped drinking.¹³

Once you are on the tablets, a drink does not undo the treatment. A 2021 SAMHSA advisory for prescribers says oral naltrexone "can be used even if patients relapse to alcohol use, as there are no adverse reactions when the substances are mixed."²

The Vivitrol shot has a firmer rule. Its Medication Guide says: "You should stop drinking before starting VIVITROL." In its main trial the shot cut heavy drinking days overall, but gains in drinking days and heavy drinking days were seen in the 8% who had not drunk in the week before the first shot and "were not evident" in the 92% who were still drinking.¹² The numbers are in how well naltrexone works.

One approach builds treatment around drinking on the drug. The Sinclair Method means taking a tablet only before planned drinking, with no requirement to quit. That schedule departs from the label's daily dose, so it is off-label in the US.^1,6 What its trials found, and where its "78%" figure comes from, is on that page.

Drinking on it: less lift, more sleepiness

Data on how drinking feels on naltrexone come mainly from human laboratory studies, where volunteers take naltrexone or a placebo and then drink a measured dose of alcohol.

A 2019 meta-analysis pooled 15 to 18 of these studies, with about 680 to 780 people, for each of its main measures. Compared with placebo, alcohol on naltrexone produced⁴:

• less craving for more alcohol
• less stimulation, the upbeat, energized part of a buzz
• more sedation, feeling sleepy or slowed down
• more low mood (9 studies)

The authors call the effects "of small magnitude."⁴ Not everyone notices a change. In 25 light and moderate social drinkers given about two drinks, naltrexone did not dampen how the alcohol felt.¹⁴ In 23 heavy drinkers, it made alcohol feel more sedating and more "unpleasant/sick," and lowered how much people liked it and wanted another drink.⁵

Lab data do not support the idea that people drink more to chase the missing buzz. In sessions where people could choose how much to drink, they drank less on naltrexone than on placebo. The effect was small and did not differ detectably between dependent and non-dependent drinkers.⁷

You are just as impaired, so plan rides the same way

Naltrexone does not protect you from alcohol's effects on your body. In the study of 23 heavy drinkers, it generally did not change how drunk people said they felt or how drunk they were on objective tests.⁵ In a study of 19 social drinkers, it did not change performance on coordination and reaction tests, or how their bodies absorbed and cleared the alcohol.¹⁵ Sinclair, who built a treatment around drinking on naltrexone, warned that opioid blockers do not block alcohol's effect on coordination, that they may sometimes increase intoxication, and that patients need strong warnings about driving.⁶

Naltrexone itself can cause dizziness. Both labels advise against driving or using heavy machinery until you know how the drug affects you.^1,12

The practical rule: if you would not drive after those drinks without naltrexone, don't drive after them with it.

Daily tablets cover any drink; targeted use means 1 hour before

How long one tablet keeps working against alcohol is not measured in the label. Its duration figures are for opioids: 50 mg blocked the effects of injected heroin for up to 24 hours.¹ Half-life and blockade timing are on how long naltrexone stays in your system. Missed doses and time of day are on naltrexone dosage.

Hangovers and side effects can feel alike

We searched PubMed and Europe PMC on October 17, 2026, and found no study that measured hangovers in people taking naltrexone, so whether they are worse is unknown.

What is known is that naltrexone's own common side effects look like a hangover. In a study of about 570 people taking it for alcohol, all of whom had stopped drinking 1 to 6 weeks before, 10% had new nausea and 7% a new headache, and 3% to 4% each reported dizziness, tiredness or trouble sleeping.^1,8 Reports collected since approval suggest most side effects come early in treatment and pass.¹ How that early stretch lines up with changes in drinking is on how long naltrexone takes to work. Full rates, with placebo for comparison, are on naltrexone side effects.

If you feel worse the morning after drinking since starting naltrexone, tell your prescriber. Options for early nausea are on naltrexone dosage. One exception needs a call, not a wait. The Vivitrol Medication Guide lists stomach pain lasting more than a few days, dark urine, yellowing of the whites of your eyes and tiredness as symptoms of liver problems to report.¹²

Still drinking heavily at 4 to 6 weeks? Change the plan

England's NICE guideline, written for people starting after withdrawal, gives a checkpoint: stop the drug if drinking persists 4 to 6 weeks after starting.⁹ Other reasons it may not be helping are on naltrexone not working.

Stopping naltrexone is not the only option. When patients return to drinking, the SAMHSA advisory suggests prescribers and patients agree on a change²:

• switch to a different medicine
• raise the dose (above 50 mg a day is outside the label's alcohol dosing, and the label warns of possible liver risk with single doses above 50 mg)¹
• add check-ins or other ways to keep motivation up
• change the type of counseling, or spend more time in it
• work out which triggers led to drinking, and how to avoid them

Two more changes may help. The VA/DoD guideline recommends at least 2 to 4 days without alcohol before starting, for a better response, and suggests the monthly shot when taking medicine reliably is a concern.¹¹ The pill and the shot are compared in naltrexone vs Vivitrol.

If one medicine doesn't help, NIAAA tells clinicians that trying another is often worthwhile.¹⁰ The closest alternative is compared in naltrexone vs acamprosate, and all the medications for alcohol use disorder on one page.

Three red lines: opioids, liver disease and withdrawal

• Opioids. Naltrexone can set off sudden, severe withdrawal in anyone with opioids in their system, including people taking it for alcohol. Stop short-acting opioids, including tramadol, at least 7 to 10 days before the first dose, and allow up to 2 weeks after methadone or buprenorphine. Opioid cough, cold and diarrhea medicines may not work while you take it.¹ Trying to override the block with more opioids can be fatal, and so can a once-safe dose after you stop: read the overdose warning.¹
• Liver disease. Naltrexone should not be used in acute hepatitis or liver failure, and it should be stopped if signs of acute hepatitis appear.^1,3 People with cirrhosis have about 5 to 10 times more naltrexone in their blood.¹ For stable (compensated) alcohol-related cirrhosis, a 2026 trial of 100 people found no worsening of liver disease attributed to the drug.¹⁷ See naltrexone and your liver.
• Withdrawal. Naltrexone does not ease alcohol withdrawal.^12,13 About half of people with AUD get some withdrawal symptoms when they stop drinking, and a small share need medical detox.¹⁰ If you drink heavily every day, get medical advice before you stop.

Mood matters too. People taking naltrexone for alcohol should be watched for depression or suicidal thinking.¹ If you have thoughts of suicide, call or text 988.¹⁸

Share your experience

What did drinking feel like after you started naltrexone? Share your experience, or read other people's naltrexone reviews.

How we checked

• Clinical claims come from the current tablet and Vivitrol labels, the APA, VA/DoD and NICE guidelines, a 2021 SAMHSA advisory, NIAAA's Core Resource and published trials.^1-3,9-12
• The lab studies and the 2026 cirrhosis trial were read as abstracts. Lab sessions are short and small, so they show how a drink feels, not how months of treatment go.
• Each quote and number was checked against our saved copy on October 17, 2026.

Programs that treat alcohol use disorder

Online programs that prescribe naltrexone for alcohol, with their posted prices, are compared on where to get naltrexone online.