What Are the Side Effects of Naltrexone to Stop Drinking?

This article describes medications used for alcohol use disorder. It is educational and not medical advice. Talk to a licensed clinician about whether any specific medication fits your situation.

Naltrexone is an FDA-approved medication for alcohol dependence; like any medication, it can cause side effects. Common issues include nausea, headache, dizziness, fatigue, appetite changes, and sleep changes, while more serious warning signs involve the liver, mood, allergic reactions, or opioid exposure. This article explains what is common, what needs prompt medical attention, who should not take naltrexone, and what to ask a clinician before deciding whether it fits your situation.

This is the stop-drinking-side-effects sub-intent entry: what people considering naltrexone as a tool to cut back commonly experience, and what to surface for a clinician. For the deeper safety overview that frames side effects in the context of alcoholism specifically — including contraindications and monitoring — see the full naltrexone side-effects explainer for alcoholism.

Key takeaways

• Common side effects such as nausea, headache, dizziness, fatigue, appetite changes, and sleep changes are often mild, but individual response varies.
• Serious warning signs include severe abdominal pain, yellow skin or eyes, dark urine, severe mood changes, allergic symptoms, or fainting.
• Naltrexone is contraindicated for people receiving opioids, dependent on opioids, in acute opioid withdrawal, or with a positive opioid screen.
• Your clinician can discuss ways to manage mild symptoms and decide whether side effects call for a dose, timing, or treatment-plan change.
• Naltrexone belongs inside a broader alcohol-treatment plan, not as a standalone quick fix.

Understanding Common Naltrexone Side Effects

When you are researching medication to help cut back on drinking, knowing what to expect physically matters. Naltrexone is FDA-indicated for the treatment of alcohol dependence, and the DailyMed naltrexone label lists possible adverse reactions across the digestive system, nervous system, sleep, mood, liver, and allergic-reaction categories.

The most common concerns people notice early are nausea, headache, dizziness, fatigue, appetite changes, trouble sleeping, or digestive discomfort. Many mild effects ease as the body adjusts, but there is no useful one-size-fits-all timeline. Your overall health, other medications, liver history, alcohol use, sleep, and hydration can all affect what you feel.

SAMHSA describes naltrexone as binding to endorphin receptors and blocking the rewarding effects of alcohol; SAMHSA also states that naltrexone can reduce cravings and consumption for some people (SAMHSA naltrexone overview). Individual response varies, and whether the potential benefit is worth the side-effect risk is a clinician's call.

The medication has not been shown to provide therapeutic benefit except as part of an appropriate addiction-management plan. In plain language: medication decisions work best when they sit alongside follow-up, behavioral support, safety screening, and a plan for what to do if symptoms change.

Mild Side Effects Versus Warning Signs

Mild nausea that improves with routine care is different from vomiting that prevents you from keeping down food or water. A headache that resolves is different from a severe headache with confusion, fainting, or vision changes. If a symptom feels severe, new, or frightening, do not try to reason your way through it alone.

Call a clinician promptly if you notice:

• persistent nausea or vomiting
• yellowing of the skin or eyes
• dark urine
• severe or worsening fatigue
• pain or tenderness in the upper right abdomen
• severe dizziness, fainting, or chest pain
• severe rash, swelling, trouble breathing, or trouble swallowing
• new or worsening depression, anxiety, hopelessness, or thoughts of self-harm

Mood changes, including depression or suicidal thoughts, have been reported with naltrexone (DailyMed naltrexone label). Alcohol use disorder and mental health conditions can also overlap, so new or worsening mood symptoms deserve prompt medical attention rather than self-monitoring alone.

How to Talk Through Mild Side Effects

Common side effects do not always mean the medication is wrong for you, but they are still worth naming clearly. A clinician may ask when symptoms started, whether they are improving or worsening, what other medications or supplements you take, whether you have liver or kidney history, and whether alcohol withdrawal symptoms are also present.

Useful topics to bring to a follow-up include:

• whether nausea, headache, dizziness, fatigue, sleep changes, or appetite changes are affecting work or daily life
• whether symptoms are getting better, staying the same, or worsening
• whether any symptom feels different from what your clinician told you to expect
• whether other medications, opioids, liver concerns, or mental health symptoms change the safety picture
• whether your broader alcohol-treatment plan still feels realistic and safe

This is also where privacy can matter. If you are worried about workplace visibility, billing, or family judgment, ask how communication, records, and follow-up visits are handled. Privacy concerns are not superficial; they affect whether people can actually stay engaged in care.

Who Should Not Take Naltrexone

Naltrexone is not appropriate for everyone, and a few situations create serious safety concerns.

The clearest contraindication is opioid use. Naltrexone is contraindicated for people receiving opioid pain medication, people dependent on opioids, people in acute opioid withdrawal, and people with a positive opioid screen or failed naloxone challenge. If opioids are in your system, naltrexone can trigger severe withdrawal.

Liver disease also needs careful evaluation. Because naltrexone is processed by the liver, people with acute hepatitis, liver failure, cirrhosis, elevated liver enzymes, or severe abdominal symptoms should discuss risk and monitoring before considering it. Pregnancy, breastfeeding, kidney disease, allergies, and mental health history are also part of the safety review.

Honest disclosure protects you. A clinician needs to know about opioid exposure, drinking volume, withdrawal history, liver symptoms, other medications, and mood changes to make a safe recommendation.

What If You Drink Alcohol While Taking Naltrexone?

Naltrexone does not create the same alcohol reaction as disulfiram (Antabuse). Disulfiram can make someone physically ill after alcohol use; naltrexone works differently by blocking endorphin receptors and reducing the reward response.

That does not make drinking risk-free. Alcohol can still impair coordination, judgment, reaction time, liver health, sleep, and mood. Some treatment protocols, including the Sinclair Method, use targeted naltrexone dosing before planned drinking occasions to reduce the brain's reward response. Whether that approach, daily naltrexone, abstinence, moderation, or another level of care fits your situation is a conversation for a licensed clinician.

What to Do Next

If you are researching side effects because you are scared about liver symptoms, withdrawal, opioids, depression, or whether it is safe to stop drinking, treat that concern as real. Telehealth can be a private starting point for some people, but severe withdrawal symptoms, chest pain, confusion, jaundice, severe abdominal pain, or thoughts of self-harm call for urgent in-person help.

Before a medication visit, write down current medications, opioid exposure, liver or kidney history, pregnancy or breastfeeding status, mental health symptoms, withdrawal history, and the side effects you most worry about. That gives the clinician a safer picture than trying to decide from an article alone.

This content is for educational purposes only and is not medical advice. Clero Health is being built for people who want to regain control over alcohol through care that's medical, evidence-based, and private. Today the site is educational, not a clinic; you can join the waitlist for launch updates.