Acamprosate vs Naltrexone: Which Is Better for Alcohol, and Can You Take Both?
By Rethink Drink.
Acamprosate and naltrexone are the two first-choice medicines in the UK for helping people stay off alcohol once they've stopped.
Neither one is simply "better".
The research suggests acamprosate has the edge at helping people stay completely alcohol-free... and naltrexone has the edge at stopping a slip from turning into heavy drinking. A doctor helps you choose, based on your health and your goal.
You might be weighing them up for the first time.
Or you might have been here before.
On calls, people often tell us they've already tried a lot... AA, rehab, a detox, acamprosate, naltrexone bought online and taken on its own. And the story we hear most is some version of "I was sober for months. Then one drink, and I was straight back where I started."
Matt, our co-founder, knows that one well. He was prescribed acamprosate himself. More on that below.
So this page compares the two: what each is, how each works, what the evidence says, who shouldn't take them, and whether you can take both... With every source linked as we go, and listed at the bottom.
This page explains two medicines. It doesn't recommend either. Whether one is right for you is a decision for a prescriber who knows your health.
In short
Same licensed goal. In the UK, both are licensed to help people who have stopped drinking to stay stopped, alongside support.
Different ways of working. Acamprosate is thought to calm the brain's over-excited state after long-term drinking. Naltrexone blocks the brain's opioid receptors, which are part of alcohol's reward.
Different strengths. In the big reviews, acamprosate did a little better at keeping people completely alcohol-free. Naltrexone did a little better at stopping a slip becoming heavy drinking. When the two were compared directly, there was no clear winner.
Different bodies suit different medicines. Acamprosate isn't suitable with kidney problems. Naltrexone isn't suitable with serious liver problems, or alongside opioids, including some common painkillers.
Can you take both? It has been studied. In the biggest trial, adding acamprosate to naltrexone didn't help more than naltrexone alone. It's a prescriber's call.
The Sinclair Method is different again. It uses naltrexone before drinking, while you're still drinking, to drink less over time. That's off-label in the UK. Acamprosate isn't part of it.
Check first: if your body depends on alcohol, stopping or cutting down too fast can be dangerous. Speak to your GP (General Practitioner) or local alcohol service before you change anything...
...Our free units calculator and AUDIT-C check give you a starting picture in a couple of minutes. They can't tell you whether your body depends on alcohol; a doctor can.
Acamprosate vs naltrexone at a glance
Acamprosate | Naltrexone (usual UK use) | |
|---|---|---|
UK licence | To help people who are dependent on alcohol stay alcohol-free, with counselling | To help prevent relapse and reduce craving, as part of a full treatment programme |
Usually started | Once you've stopped; UK guidelines say it can be started before or during a medically assisted detox | Once you've stopped, or during or after a detox |
How it's thought to work | Helps rebalance the brain's "accelerator" and "brake" chemicals after long-term drinking | Blocks opioid receptors, reducing part of the reward from alcohol |
What the research says it's better at | Staying completely alcohol-free | Stopping a slip turning into heavy drinking |
Processed by | The kidneys | The liver |
Main reasons it may not suit you | Kidney problems; breastfeeding | Serious liver problems; taking or needing opioids |
How you take it | Daily, as prescribed | Daily, as prescribed |
A table can't tell you what's right for you. It's a starting point for a conversation with a doctor.
One word of warning before we go further...
Naltrexone has two completely different uses. Everything in this table is its usual NHS use: daily, after stopping, to stay stopped. The Sinclair Method uses it another way, and we'll keep the two apart all the way down.
What is acamprosate?
Acamprosate is a prescription medicine for alcohol dependence. You might also see it under the brand name Campral.
Its UK licence is to help people who are dependent on alcohol keep away from alcohol once they've stopped, and the product information says it should be combined with counselling.
It's taken daily, as prescribed.
It's the most prescribed of the alcohol medicines by GPs in England, by a LONG way. In the 12 months to July 2026, GP practices issued about 171,000 prescriptions for acamprosate, against about 20,000 for naltrexone (and that naltrexone figure includes prescriptions for opioid problems too), according to OpenPrescribing.
How does acamprosate work?
Your brain runs on a balance of chemical signals. Some speed things up (glutamate, the accelerator). Some slow things down (GABA, the brake).
Years of heavy drinking push that balance out of shape... and when you stop, the system can be left over-excited.
Acamprosate is thought to help settle that balance back down. The UK product information says it may work by supporting the brain's calming signals and dampening glutamate.
That "may" matters. Nobody fully knows how it works.
What matters more to most people is what it doesn't do. It isn't a deterrent, so it won't make you ill if you drink. And the product information is clear that it doesn't protect you from the harm of continued heavy drinking. It's built for staying stopped.
What is naltrexone, and how does it work?
Naltrexone is an opioid antagonist (an opioid blocker).
When you drink, alcohol triggers the release of endorphins, your body's own feel-good chemicals. They land on opioid receptors in the brain... And that provides a reward.
Naltrexone sits on those receptors, blocking them, so the endorphins have no place to land.
In its usual UK use, it's taken daily, as prescribed, once you've stopped drinking. Its UK licence is to reduce the risk of relapse, support abstinence and reduce craving, as part of a full treatment programme (Adepend product information).
We've written a full explainer here: Naltrexone for alcohol in the UK.
Which is better, acamprosate or naltrexone?
It depends what you're trying to do. And the differences are smaller than most comparison pages suggest.
Here's what the biggest reviews found.
Acamprosate and staying completely alcohol-free. A Cochrane review pooled 24 trials, with nearly 7,000 people who had already stopped drinking. Acamprosate lowered the risk of going back to any drinking (to 86% of the risk on a dummy pill), and added around 11 more alcohol-free days on average. Its effect on heavy drinking wasn't clear.
Naltrexone and heavy drinking. A separate Cochrane review pooled 50 trials, with nearly 7,800 people. Naltrexone lowered the risk of going back to heavy drinking (to 83% of the risk on a dummy pill). Its effect on whether people drank at all was less clear.
The UK clinical guidelines put it in plain terms too: naltrexone can reduce the risk that a lapse turns into a full relapse.
When researchers put the two side by side:
A 2013 review in the journal Addiction found acamprosate had the larger effect on staying alcohol-free, and naltrexone the larger effect on heavy drinking and craving. The authors were careful, though. Most of the comparison was indirect, few acamprosate trials reported heavy drinking, and some of the gaps could be chance.
A 2014 review in JAMA looked at 123 studies. Trials that compared the two directly found no significant difference between them.
A 2023 update in JAMA (118 trials) backed both as first-choice medicines, alongside psychological support. Roughly, for every 11 people treated with acamprosate, one more avoided returning to drinking than would have on a dummy pill. For daily naltrexone, it was about one in 18 for any drinking, and one in 11 for heavy drinking.
Read that again... Both help. Neither works for everyone. And both were tested alongside support.
In UK guidelines, the choice between them comes down to things like your goal, your kidney and liver health, whether you take opioids, and what you'd prefer.
What happened when Matt took acamprosate?
It happened to Matt... over, and over. His longest time without a drink was six months, and he thought he'd cracked it.
He was in secondary care (a specialist NHS alcohol service) with The Recovery Partnership, going to their meetings... They prescribed acamprosate, and he went to AA alongside it.
In his words: "I wasn't drinking. But I wasn't free from it either... I couldn't stop thinking about it. And I was miserable."
He took the tablets. He didn't drink. But alcohol had never been more involved in his life.
The prescription was for six months... Six months and two weeks later, he was drinking again. Heavier than ever.
Plenty of people use acamprosate, with support, to stop and stay stopped.
For Matt, the problem wasn't one medicine or another... It was the whole abstinence approach.
Those six months put time between him and his last drink. They didn't change what a drink meant to him... His brain remembered EXACTLY what alcohol felt like.
That's Matt's experience, certainly not a promise or a verdict for yours. He's told the whole story here: Once an alcoholic, always an alcoholic: really?
If "sober for months, then one drink" sounds familiar, you're not alone. And it isn't a willpower problem. It's covered here: Understanding alcohol relapse.
Who shouldn't take acamprosate or naltrexone?
Your prescriber checks this. But it helps to know what they're looking for.
Acamprosate may not be suitable if you:
Have kidney problems. It's cleared by the kidneys, so your kidney function is checked first.
Are breastfeeding.
Are pregnant or planning a pregnancy. UK guidance says alcohol medicines should be avoided in pregnancy unless the benefit outweighs the risk.
Are a child or an older adult. The Campral leaflet says it isn't recommended for either.
Naltrexone may not be suitable if you:
Have serious liver problems, including hepatitis or liver failure. It's processed by the liver, so your liver is checked first.
Have severe kidney problems.
Take, use or are likely to need opioids. That includes some prescription painkillers like codeine and tramadol, methadone, and some cough medicines. Taking naltrexone while dependent on opioids can cause dangerous withdrawal.
Are pregnant or breastfeeding.
One more thing worth knowing about naltrexone. After you stop taking it, you can be more sensitive to opioids than before. Your prescriber will talk you through that.
Because acamprosate isn't processed by the liver, UK guidelines say it's probably the safer of the two for people with advanced alcohol-related liver disease. And because naltrexone blocks opioids, acamprosate is the one that doesn't get in the way of opioid painkillers. That's often what decides it.
That's all down to your prescribing doctor to discuss with you.
More on naltrexone and other medicines: Does naltrexone interact with other medications?
What are the side effects?
In brief, from the UK product information.
Acamprosate: the most common is diarrhoea. Others listed as common include stomach pain, nausea or being sick, wind, itching, a rash, and changes in sex drive. In the Cochrane review, diarrhoea was the only side effect reported more often than on a dummy pill.
Naltrexone: the most commonly listed include nausea, stomach pain, headache, trouble sleeping, feeling anxious or restless, joint and muscle aches, and feeling tired or weak.
Most side effects are mild. If anything worries you, speak to your prescriber or pharmacist. Don't stop or change a medicine without talking to them.
More detail: Naltrexone side effects in plain English.
Can you take acamprosate and naltrexone together?
On calls, people sometimes ask us this.
It has been studied. The biggest trial is COMBINE, run across 11 US sites, with 1,383 people who had recently stopped drinking, over 16 weeks.
What it found:
Naltrexone, with regular check-ins from a healthcare professional, helped people have more alcohol-free days and delayed a return to heavy drinking.
Acamprosate showed no benefit over a dummy pill in that trial, with or without extra therapy.
No combination did better than naltrexone alone.
That's one trial, though. Other trials, pooled in the Cochrane review above, did find a benefit for acamprosate, and researchers still debate why COMBINE didn't.
The UK product information records that naltrexone raises the level of acamprosate in the blood, and neither medicine's leaflet lists the other as one to avoid.
So it isn't ruled out. But there's no strong evidence that two is better than one... and whether to combine them is your prescriber's decision, not something to try on your own.
How is The Sinclair Method different?
Everything above is about staying stopped.
The Sinclair Method has a different goal altogether. So it's worth being clear:
Two completely different ways of using naltrexone, with
Two completely different relationships with drinking, for
Two completely different goals.
In its usual NHS use, naltrexone is taken daily, after you've stopped, to help you stay stopped.
The Sinclair Method uses naltrexone before drinking, at a time your prescriber sets, while you're still drinking.
With the reward blocked, every drink is a shift with no pay... So over time, the brain questions the relationship, the desire weakens, and you drink less. Or stop, if you choose to. The science behind it is explained here: What is pharmacological extinction?
It's not the medication itself that makes the method, it's the protocol of how to take it.
That use is off-label in the UK and outside UK guidelines. Doctors can prescribe off-label, but they take responsibility for it, which is one reason many GPs won't: Can I get naltrexone from my GP?
Acamprosate isn't part of The Sinclair Method. It's built for staying stopped, and it isn't designed to work while you're drinking.
So if you're comparing the two because you want to drink less rather than stop, that changes the conversation with your doctor. Say so. Nalmefene is the medicine licensed in the UK to help some people cut down, and NICE says cutting down can be the right goal for some people: Alcohol treatment options in the UK.
The Sinclair Method is explained in full here: What is The Sinclair Method? You may have seen our 78% figure. It comes from Dr Sinclair's own clinics in Finland, not a controlled trial; controlled trials show a smaller, real effect, and results vary. The evidence, in full: what the research really shows.
Neither medicine is meant to work alone. NICE recommends both acamprosate and naltrexone alongside psychological support.
Taking a tablet cannot change our habits. Over time, the medicine can quieten the desire... But the routines you've built around a drink over years? That's the real work.
Support matters on The Sinclair Method too: Why support matters on The Sinclair Method.
Common questions
Is acamprosate the same as Campral?
Yes. Campral is a brand name for acamprosate. Your pharmacist may give you a different brand or a generic version.
Can I drink on acamprosate?
It won't make you ill if you drink. But it's licensed to help you stay alcohol-free, and the product information says it doesn't protect you from the harm of continued drinking. If you're drinking while on it, tell your prescriber. UK guidelines say they should review whether it's helping.
Do I have to stop drinking before starting either one?
For their licensed use, yes, usually. UK guidelines say acamprosate can be started before or during a medically supervised detox. If your body depends on alcohol, a doctor needs to look at that first: Do I need a detox first?
Can my GP prescribe acamprosate or naltrexone?
Both can be prescribed by a GP, a specialist alcohol service or a hospital. In many areas a specialist service starts them, and your GP may take over later.
Which is better for cravings?
Both are described as helping with cravings. In the 2013 review, naltrexone's effect on craving was a little larger, but the difference wasn't clear-cut.
Can I switch from one to the other?
People do, if one isn't suiting them. It's a decision for your prescriber, who'll look at why, and at your liver, kidneys and other medicines.
If you'd like support from us
Rethink Drink is a UK coaching service built around The Sinclair Method. Our programmes include a consultation with an independent prescribing doctor, who decides whether treatment is suitable for you. Any prescription is dispensed by an independent partner pharmacy. Our coaches work with you, week by week, on everything around it.
And whatever happens, you can talk to someone today. Drinkline, the national alcohol helpline, is free and confidential: 0300 123 1110.
Please look after yourself
This page is here to help you understand your options. It isn't medical advice, and it can't replace a conversation with a doctor who can ask qualifying questions.
Before you change how much you drink or start any medication, speak to your GP or a prescriber.
We really hope this post helps. If you have any questions, you can contact us here.
The Rethink Drink team
Sources
Viatris. Acamprosate gastro-resistant tablets: Summary of Product Characteristics (emc, updated December 2025). https://www.medicines.org.uk/emc/product/2729/smpc
Merck Serono. Campral EC gastro-resistant tablets: Patient Information Leaflet (emc, revised August 2026). https://www.medicines.org.uk/emc/files/pil.986.pdf
Adepend film-coated tablets (naltrexone): Summary of Product Characteristics (emc). https://www.medicines.org.uk/emc/product/3559/smpc
Department of Health and Social Care. UK clinical guidelines for alcohol treatment, chapter 10: pharmacological interventions. https://www.gov.uk/guidance/clinical-guidelines-for-alcohol-treatment/10-pharmacological-interventions
NICE. Alcohol-use disorders: diagnosis, assessment and management of harmful drinking (high-risk drinking) and alcohol dependence (CG115). https://www.nice.org.uk/guidance/cg115
NHS. Alcohol use disorder: treatment. https://www.nhs.uk/conditions/alcohol-use-disorder/
Rösner S and colleagues. Acamprosate for alcohol dependence. Cochrane Database of Systematic Reviews, 2010 (CD004332). https://www.cochrane.org/evidence/CD004332_acamprosate-alcohol-dependent-patients
Rösner S and colleagues. Opioid antagonists for alcohol dependence. Cochrane Database of Systematic Reviews, 2010 (CD001867). https://www.cochrane.org/CD001867/ADDICTN_opioid-antagonists-alcohol-dependence
Maisel NC, Blodgett JC, Wilbourne PL, Humphreys K, Finney JW. Meta-analysis of naltrexone and acamprosate for treating alcohol use disorders: when are these medications most helpful? Addiction, 2013; 108(2): 275 to 293. Summary: https://www.drugsandalcohol.ie/26544/
Jonas DE and colleagues. Pharmacotherapy for adults with alcohol use disorders in outpatient settings: a systematic review and meta-analysis. JAMA, 2014; 311(18): 1889 to 1900. https://jamanetwork.com/journals/jama/fullarticle/1869208
McPheeters M and colleagues. Pharmacotherapy for alcohol use disorder: a systematic review and meta-analysis. JAMA, 2023; 330(17): 1653 to 1665. https://pubmed.ncbi.nlm.nih.gov/37934220/
Anton RF and colleagues. Combined pharmacotherapies and behavioral interventions for alcohol dependence. The COMBINE Study: a randomized controlled trial. JAMA, 2006; 295(17): 2003 to 2017. https://jamanetwork.com/journals/jama/fullarticle/202789
Bennett Institute, University of Oxford. OpenPrescribing (NHS England prescribing data, August 2025 to July 2026). https://openprescribing.net/
