Neither naltrexone injection nor the oral form works best for everyone. Your routine and health history shape the right choice. This guide covers both forms for alcohol use disorder. See our guide to medications for alcohol use disorder for other options. If you are exploring other medication options for alcohol use disorder, our guide to acamprosate details how it works and its side effects.
We are an editorial team that reviews public health sources. We do not offer treatment. Do not use this page to begin or end a drug. Ask a doctor about side effects and which form works for you.
Naltrexone for Alcohol Use Disorder: Pill or Shot?
Naltrexone injection vs oral options give you two paths to the same drug. Both carry naltrexone, but they enter the body in distinct ways. You take a pill by mouth every day. A healthcare provider gives you a shot once a month.[1]
Naltrexone works by blocking opioid receptors in the brain. This can lower the feeling of a high from drinking. That helps some people cut back or stop. It is one piece of a bigger plan. Counseling and support groups are often part of that plan. For a fuller look at medication and counseling for AUD, our guide covers the main treatment options available.
This guide looks only at alcohol use disorder. It does not borrow data from opioid use disorder studies to say one form beats the other for alcohol. See our guide on how naltrexone works to learn more about how naltrexone works.
Naltrexone Injection vs Oral: Key Differences
Both the daily pill and the monthly shot aim to lower alcohol cravings. Your life choices drive which one fits. The routine is the main thing that shifts.
Once daily
oral naltrexone is taken by mouth as prescribed[2]
Every 4 weeks
extended-release injectable naltrexone is given by a healthcare professional[3]
Comparing the Naltrexone Shot and Pill
This table lists the practical sides of each choice. It does not say one beats the other. Convenience varies for each person. It relies on your schedule, care access, and habits.
| Feature | Oral Naltrexone | Extended-Release Injectable Naltrexone |
|---|---|---|
| Route & Routine | Taken by mouth once daily as prescribed[2] | Administered by a healthcare professional once every four weeks[3] |
| Practical Advantages | No clinic visits needed; can be taken at home[2] | Removes the need for daily reminders; ensures consistent delivery[3] |
| Ask Your Clinician | "How can I build a habit to remember my daily dose?" | "Do I need to travel far for my injection appointments?" |
Look at what stops you from keeping a plan. If you tend to miss pills, a monthly rhythm may help. If you dislike needles or clinics, the pill may suit you. Take these points to your doctor. They can help you find the right match.
Before using naltrexone, your clinician will check for any recent or current opioid use. They will figure out how long you must stay opioid-free. Ask your clinician how this safety check fits your case.
How the Monthly Injection Schedule Works
Getting the monthly naltrexone injection takes a trip to a provider for each dose.[3] You need steady access to a clinic that gives this service. The injection delivers the medicine. It does not take the place of ongoing care. You will still go to follow-up visits to talk about progress. Our guide to monitoring alcohol medication progress helps you track how the treatment is working between those follow-up visits.
Start
Discuss options with your clinician and choose a formulation that fits your lifestyle.
Routine
Follow the prescribed plan, whether that is taking a pill daily or attending an injection visit every four weeks.[2][3]
Follow-up
Return for regular check-ins to review how you are doing and adjust support if needed.
This timeline shows the usual pattern of care. It does not serve as a dosing instruction or treatment protocol. Your doctor’s advice and your needs shape your specific schedule.
Is the Monthly Naltrexone Injection More Effective?
People with alcohol use disorder can find help from either naltrexone form. Direct evidence compares the two, and researchers have also tested each against a placebo. A head-to-head study, known as the XON trial, directly compared the monthly naltrexone injection to the daily pill. Yet, the current direct evidence does not show that one formulation beats the other.
An AHRQ evidence review looked at the daily pill. It found that oral naltrexone lowers the risk of going back to heavy drinking compared with placebo.[4] In other words, taking the medication can help keep heavy drinking days lower than a sugar pill.
Another 24-week randomized trial looked at extended-release injectable naltrexone. It found fewer heavy-drinking days than placebo for patients who did not drink in the week before starting.[5] These studies track different results. They do not show which form works better.
The American Psychiatric Association says evidence is limited when comparing long-acting injectable naltrexone to oral forms.[6] They suggest it may help with adherence.[6] The injection lasts for a month, so you do not have to remember a daily dose. This can help if you struggle with consistency. Talk with your doctor about which option fits your life and goals.
Staying Safe with Opioids and Alcohol Withdrawal
Before you start naltrexone, share any recent or current opioid use with your healthcare provider. This includes prescription pain medicines.
Because naltrexone blocks opioid effects, it can get in the way of opioid-based pain drugs and pain management.[7] Tell your clinician you use naltrexone before any surgery or when you need pain care. They can then tweak your pain plan to keep you safe.
You must be opioid-free before starting naltrexone. Your clinician decides how long you need to wait. Do not guess if you are ready. A clinician must confirm it is safe to begin treatment.[7]
Naltrexone is not a cure for acute alcohol withdrawal. If you drink a lot, do not try to quit on your own. Reach out to a doctor or a treatment program for safe medical help. If you have already started treatment, our guide to relapse on alcohol medication outlines the safety steps to take next.
As naltrexone’s opioid blockade wanes or after treatment ends, reduced opioid tolerance can increase overdose risk if a person returns to opioid use.[8] This is a serious safety issue for your care team to address. See our guide on naltrexone and opioid safety for more details.
If you suspect an overdose, call 911 or go to the nearest emergency room immediately.
Naltrexone Injection vs Oral: Side Effects to Watch
Side effects can happen with both forms of naltrexone.[8][7] The pill and the shot may bring different issues.[8][7] Knowing what is common helps you know when to call your doctor.
For the daily pill, commonly reported side effects include nausea, headache, dizziness, and tiredness.[8] Nausea and injection-site reactions have been reported with the monthly injection.[7] Severe injection-site reactions have also been reported and may need medical care or even surgery.[7]
Reach out to your prescriber if you feel unwell or notice anything unusual. Talk with them before changing any medications.
Get medical help right away if you see signs or symptoms of acute hepatitis.
Tracking these changes can be hard. You do not have to handle it alone. Our guide on managing medication side effects offers tips for tracking symptoms. It also helps you get ready for talks with your care team. Stay in touch with your prescriber. They can help decide if your plan needs changes.
Picking the Right Plan and Talking About Costs
It is up to you to pick between a monthly shot and a daily pill. Your daily routine, past health, and insurance shape this choice. Use the tools below to get ready for a talk with your prescriber.
Does Naltrexone Work Like Ozempic? Do Doctors Steer Clear of It?
Naltrexone is not the same as Ozempic. Naltrexone acts as an opioid antagonist.[8] Ozempic uses semaglutide, which is a different kind of drug. These two medicines work in distinct ways. You cannot switch one for the other.
Some people think doctors do not like naltrexone, but that is not true. Big guidelines list it as a standard choice for alcohol use disorder.[6] It is meant for patients who fit well.[6] Your doctor’s advice will match your specific health needs.
What Should You Discuss With a Clinician?
This self-check is for information only and isn't a diagnosis. It helps you prepare questions for your care team.
Questions to Take to a Clinician and Insurer
Your ticks are saved on this device only.
Look up your exact benefits with your plan. To learn how plans treat these drugs, read our guide on naltrexone insurance coverage.
Frequently Asked Questions
What is the most effective way to take naltrexone for alcohol use disorder?
No single form is best for everyone. Evidence is limited when comparing the shot to the pill. The shot may help people stick to their plan better.[6] Talk to a clinician about your routine and health.
How long does a naltrexone injection last?
A healthcare professional gives the shot once every four weeks.[3] You do not take a pill every day. Ask your prescriber how this schedule fits your life.
Does the injection work better than the pill for alcohol use disorder?
We do not know if the shot works better than the pill. Evidence is limited for alcohol use disorder.[6] Do not mix up results from other conditions.
Why might I feel unusual or unwell while taking naltrexone?
Common side effects of the pill include nausea, headache, dizziness, and tiredness.[8] The shot can cause nausea and soreness at the injection site.[7] For non-emergency side effects, contact your prescriber. For signs of an overdose, seizures, severe confusion, hallucinations, a high fever or racing heart during withdrawal, call 911 or go to the nearest emergency room now. For thoughts of suicide or self-harm, call 911 or go to the nearest emergency room now; you can also call or text 988.
Is naltrexone like Ozempic?
No, they are different medicines. Naltrexone is an opioid antagonist.[8] Do not use Ozempic info to answer questions about naltrexone.
Why don’t doctors like naltrexone?
Doctors do not dislike naltrexone. It is a standard option for alcohol use disorder.[6] Your clinician picks the best fit for your health history.
Can oral naltrexone be started while someone is still drinking?
The APA guidance cited here does not state that someone must stop drinking before starting oral naltrexone. For people with alcohol use disorder and co-occurring opioid use disorder, it includes those who want to abstain from opioids and either abstain from or reduce alcohol use, provided they can abstain from opioids for an appropriate time before starting naltrexone.[6] In a 24-week injection trial, a subset who abstained from drinking during the week before their first dose had reduced heavy-drinking days compared with placebo; this finding does not establish an abstinence requirement for starting the injection or the pill.[5] Ask your clinician whether and when to start based on your situation.
