Acamprosate Side Effects and Safety

Acamprosate Side Effects and Why It Is One of the Safer Choices

Here is the plain answer most people come looking for. Acamprosate is generally well tolerated, the most common side effect is diarrhea, and it is not a controlled substance, not addictive, and safe to keep taking even if you slip and drink. Most side effects are mild, most ease as your body settles, and almost nobody has to stop the medicine because of them.

That is the whole reassurance up front. Acamprosate—brand name Campral—is not a sedative and has no high of its own. It is there to do one quiet job: help you stay stopped once you have stopped.

The sections below cover the side effects worth knowing, whether acamprosate is a controlled substance, what happens if you drink on it, whether it causes weight gain, the one thing your kidneys have to do with it, and how long people usually stay on it. For the full picture of how the medicine works and who it fits, start with the main guide on how acamprosate protects early sobriety.

Common Acamprosate Side Effects

Most people tolerate acamprosate well, and when side effects do show up they are usually the mild, settle-down-on-their-own kind. They tend to be loudest early and quieter as the weeks go on.

The ones people notice most:

• Diarrhea—the single most common complaint, usually mild and often temporary. Spacing the doses out and keeping fluids up helps, and it is rarely a reason to quit.
• Nausea or stomach upset—common early, generally settles. Taking the tablets with meals can take the edge off.
• Gas or bloating—a nuisance more than a worry.
• Itching—less common, usually mild.
• Anxiety or trouble sleeping—occasional, and they often overlap with early sobriety itself, when sleep and mood are already unsettled.

Across the evidence, acamprosate’s side effects are mild enough that very few people stop the medicine because of them, and digestive complaints like diarrhea are the main thing to plan around^[1]. The takeaway is simple: for most people the side effects are a brief nuisance, not a wall—and stopping over a manageable stomach issue means giving up protection you may need.

Is Acamprosate a Controlled Substance

No. Acamprosate is not a controlled substance, it is not scheduled by the DEA, and it has no potential for abuse or addiction. There is nothing in it to get high on, no buzz to chase, and no withdrawal if you stop. Because it is not controlled, any licensed prescriber can write it, refills are straightforward, and you are not signing up for a drug that could become a new problem.

This is one of the quiet advantages of the medicine. It works on the brain’s glutamate system to calm the over-revved, anxious feeling that lingers for weeks after the last drink—it does not touch the reward or opioid pathways that drive a high. No reward signal means no abuse potential.

Can You Drink Alcohol on Acamprosate

Yes, and this is the part that trips people up. Drinking on acamprosate will not make you sick the way Antabuse (disulfiram) does—there is no flushing, no vomiting, no dangerous reaction. Acamprosate is not a punishment drug. And here is the message that matters most: if you slip and drink, keep taking it. The medicine is there to help you get back on track, and quitting it after a slip throws away the very thing built to catch you.

A slip is not a failure of the medication, and it is not a reason to stop. Acamprosate is the treatment most directly designed to protect abstinence and lower the odds of a full return to drinking, and it does that best when you stay on it through the bumps^[2]. Think of a slip as a pothole, not the end of the road.

Does Acamprosate Cause Weight Gain

No. Acamprosate is not associated with weight gain. It is not a steroid or a hormone, it does not slow your metabolism, and weight change is not a recognized effect of the medicine. If anything tilts the other way, it is the early stomach upset—some people get a little nausea or diarrhea that briefly dampens appetite—but that usually settles and is not a reason to expect to put on pounds.

If your weight is shifting in early recovery, remember how much else is changing at once. Cutting the empty calories of heavy drinking, eating and sleeping differently, and your body relearning a routine all move the needle far more than acamprosate does. Raise any weight change with your provider—but you can take this medicine without bracing for weight gain.

Acamprosate and Your Kidneys

Here is the one safety detail that genuinely shapes who takes acamprosate. The medicine is cleared by your kidneys, not your liver, so in significant kidney problems the dose is lowered or the drug is avoided. For most people this is a non-issue—it just means a quick check before you start. For people with reduced kidney function, it is a real conversation, because the medicine can build up if the kidneys cannot clear it well.

That same kidney-not-liver pathway is also why acamprosate is often the preferred choice for people with liver disease, where some other options are riskier. The trade is simple to keep straight: easy on the liver, but it leans on the kidneys.

How Long to Stay on Acamprosate

The answer is as long as it is helping—and for most people that means months, often up to a year, as one part of a recovery plan. Acamprosate works on the lingering brain changes that drive early relapse, the restless, anxious pull that can last well past the first sober week, so it earns its keep across that vulnerable stretch rather than in a quick course.

There is no fixed finish line. Any decision to stop should be made with your provider, based on how stable you feel and what else is supporting you—counseling, peers, the life you are rebuilding—not on an arbitrary date. Staying on it is not a crutch; it is using a tool for exactly as long as the tool helps.

Getting Help

If you are reading this far down a page about side effects, you are not looking for a reason to quit treatment—you are trying to do it right. Hold on to the plain version. Acamprosate is well tolerated, it is not a controlled substance and not addictive, and it is safe to keep taking even if you slip. That is a medicine you can lean on without fear, and a sobriety that gets steadier the longer you protect it.

You do not have to figure this out alone. A provider can walk you through whether acamprosate, naltrexone for alcohol cravings, or another approach fits your situation, and none of those choices is a failure. Pairing the medicine with support is what makes recovery from alcohol use disorder stick.

When you are ready to find help near you, explore treatment centers →. For free, confidential help any time, call SAMHSA’s National Helpline at 1-800-662-HELP (4357). And if you or someone you love is in danger right now, call or text 988, or call 911 for a medical emergency.

Written by

Jessica Miller

Editorial Director

Jessica Miller is the Editorial Director of Addiction Help. Jessica graduated from the University of South Florida (USF) with an English degree and combines her writing expertise and passion for helping others to deliver reliable information to those impacted by addiction. Informed by her personal journey to recovery and support of loved ones in sobriety, Jessica's empathetic and authentic approach resonates deeply with the Addiction Help community.

Reviewed by

• Fact-Checked
• Editor

Kent S. Hoffman, D.O.

Co-Founder & Chief Medical Officer

Kent S. Hoffman, D.O. has been an expert in addiction medicine for more than 15 years. In addition to managing a successful family medical practice, Dr. Hoffman is board certified in addiction medicine by the American Osteopathic Academy of Addiction Medicine (AOAAM). Dr. Hoffman has successfully treated hundreds of patients battling addiction. Dr. Hoffman is the Co-Founder and Chief Medical Officer of AddictionHelp.com and ensures the website’s medical content and messaging quality.