Last Updated on July 26, 2026

Naltrexone and naloxone are different medications with different purposes. Naloxone (Narcan) is an emergency medication that rapidly reverses an opioid overdose. Naltrexone is a prescription medication that works to reduce alcohol’s rewarding effects, which can make alcohol feel less compelling over time. Although these medications’ names are similar, the medications are not interchangeable.

You’ve heard about naltrexone to help you drink less. You look it up, and suddenly you’re reading about Narcan, opioid overdoses, and emergency rooms.

Wait… you think. What is this medication, anyway?

Many people researching naltrexone have the same reaction — if you do, you may not be reading about naltrexone at all. The words “naltrexone” and “naloxone” (or Narcan, which is a well-known brand name for naloxone) are remarkably similar, and search results sometimes mix them up.

But naloxone and naltrexone are not the same thing. The medications have some commonalities, but they’re used in completely different situations and for different purposes.

Naltrexone vs. Naloxone: The Quick Answer

• Naloxone is an emergency medication that rapidly reverses an opioid overdose.
• Naltrexone is a prescription medication used over time to help treat alcohol use disorder and opioid use disorder after detoxification. It works to reduce alcohol’s rewarding effects, which can make alcohol feel less compelling over time, including for gray-area drinkers who don’t identify with a particular diagnosis.
• Although their names are similar and both act on opioid receptors, they serve very different purposes.
• Naloxone is commonly sold as Narcan®. Naltrexone is available as generic tablets and as the extended-release injection Vivitrol®.

How Naltrexone Works — And How It Supports Alcohol Reduction or Sobriety

Naltrexone is a maintenance medication, not an emergency one, that can help people manage their alcohol cravings. It works to lessen the rewarding effects of alcohol, often leading to fewer cravings over time. 

Naltrexone functions by blocking opioid receptors involved in the brain’s reward system. Alcohol normally activates this system, making drinking feel rewarding. Naltrexone reduces that reward.

As Sunnyside co-founder Ian Andersen described it: “Drinking might feel different — and that’s the point. Less exciting. Less rewarding. Sometimes just… less fun. That’s the medication doing its job.”

Unlike disulfiram (Antabuse), naltrexone doesn’t make you sick if you drink alcohol.

Whether you’re working toward moderation or abstinence, it’s intended to make alcohol less reinforcing so intentional choices become easier. It’s available with a prescription from your provider. You can also access once-daily compounded naltrexone—along with a robust system of behavioral change tools, support, and community—through Sunnyside Med.

How Naloxone Works — And Why It Has to Work Fast

Naloxone is an emergency medication used to reverse an opioid overdose. It rapidly displaces opioids from opioid receptors, restoring normal breathing within minutes in many cases.

Its speed is what makes it lifesaving, but it’s also short-acting. Naloxone has a plasma half-life of about one to two hours (Saari et al, 2024), so its effects can wear off before some opioids have left the body. That’s why anyone who receives naloxone should still receive emergency medical care, even if they seem to recover.

Naloxone is available as a nasal spray (Narcan) and other formulations. In the United States, Narcan nasal spray is available over the counter, making it easier for family members, caregivers, and bystanders to respond quickly during an opioid overdose.

Unlike naltrexone, naloxone doesn’t reduce alcohol’s rewarding effects. The two medications act on the same opioid receptors, but they’re designed for entirely different situations. One is an emergency rescue medication, while the other is a long-term treatment.

What Being Prescribed Naltrexone Actually Means

Being prescribed naltrexone for drinking doesn’t mean your clinician thinks you’re overdosing or that your drinking is worse than you realized.

It means they’re offering an evidence-based medication that can help reduce alcohol’s rewarding effects. For many people, that makes changing their drinking patterns feel more manageable without relying on willpower alone.

Naltrexone has been FDA-approved to treat alcohol dependence since 1994 and has been studied extensively as part of alcohol use disorder treatment. However, it’s not only for people who’ve reached a crisis or decided on lifelong abstinence. Some people use naltrexone because they want to drink less, others because they’ve struggled to cut back on their own, and others because they’re working toward sobriety.

As one Sunnyside Med member put it: “I feel as though the naltrexone is a godsend. I’m really enjoying having the ‘noise’ quieted.”

How to Access Naltrexone with Sunnyside Med

Now that you know what naltrexone actually is—and what it isn’t—you can decide whether it’s a tool you’d like to discuss with a clinician.

If you’re interested in trying daily oral naltrexone, a clinician can determine whether it’s an appropriate option based on your medical history, current medications, and drinking goals.

Sunnyside Med combines 100% online, clinician-guided compounded naltrexone with a habit-change app, human coaching, and daily tracking tools designed to support lasting behavior change. A licensed clinician reviews every application, and members have ongoing access to their care team throughout treatment.

Among active Sunnyside Med members with at least 50% app engagement, 78% achieved a meaningful reduction in drinking over 12 weeks. Individual results vary.

If you’re ready to explore whether naltrexone could help you drink less, you can complete Sunnyside Med’s online assessment in just a few minutes to learn whether you’re eligible.

Frequently Asked Questions (FAQ): Naltrexone vs. Naloxone

Is naltrexone the same as naloxone?

No. Naloxone is a fast-acting emergency medication that reverses an opioid overdose. Naltrexone is a prescription medication that works to reduce alcohol’s rewarding effects, which can make alcohol feel less compelling over time (and is available through Sunnyside Med). Although the names are similar, they’re used for completely different purposes.

What is naloxone?

Naloxone is an emergency medication that rapidly reverses an opioid overdose. Narcan® is the best-known brand of naloxone nasal spray and is available over the counter in the United States.

Is naltrexone the same as Narcan?

No. Narcan® is a brand name for naloxone, the emergency medication used to reverse opioid overdoses.

Does naltrexone make you sick if you drink?

No. That reaction comes from disulfiram (Antabuse), a different medication. Naltrexone works by reducing alcohol’s rewarding effects, which can make drinking feel less reinforcing over time.

Why are naltrexone and naloxone so easy to confuse?

Their names differ by only a few letters, and both medications interact with opioid receptors. Despite those similarities, they’re used for completely different purposes: naloxone for emergency overdose reversal and naltrexone for long-term treatment.

How long does naltrexone stay in your system compared to naloxone?

Naloxone works within minutes and has a plasma half-life of about one to two hours. Naltrexone remains active much longer, which is why it’s prescribed as a daily tablet or a monthly extended-release injection rather than as an emergency medication.

Do I need to have a serious drinking problem to take naltrexone?

No. Many people consider naltrexone because they drink more than they want to, not because they’ve reached a crisis. Whether it’s appropriate depends on your drinking pattern, your medical history, and your clinician’s assessment.

Naltrexone is a prescription medication. This content is for educational purposes only and should not be taken as medical advice. A licensed clinician reviews every Sunnyside Med application to determine whether treatment is appropriate.

Sunnyside is the Perfect Companion for Your Naltrexone Journey

Sunnyside is the #1 mindful drinking app. Since 2020, we’ve been honing our harm-reduction approach and have helped over 400,000 people cut out 22 million drinks from their baseline habits. 96.7% of our members report success in drinking less, and in a third-party study, our approach was demonstrated to reduce weekly drinking by 33% after 12 weeks. 

Think of Sunnyside as the front door for anyone who wants to change their relationship with alcohol. If you want to drink less, we can help you get there. If you want to eventually quit, but want to take a gradual approach, we can make that happen.

When you sign up for Sunnyside, you’ll take a quick 3-minute quiz, then hop into the app. It’s as simple and quick as that. 

We’ll give you weekly plans to gradually reach your drinking goals, and we’ll provide nudges, coaching, exercises, and advice to help you get there. 

We have daily tracking and journaling tools, including the option to chat with a real human coach at any time. And our state-of-the-art analytics help you track your progress over time. 

Sunnyside is a full-featured mindful drinking app. Naltrexone will actively help you reduce cravings around alcohol, and Sunnyside will help you understand your triggers and patterns, giving you a healthy system for habit change. 

If you choose to stop taking naltrexone, the Sunnyside app remains a tool you can keep using to maintain your healthy habits. 

Everyone who signs up for Sunnyside gets a free 15-day trial. After that, the subscription is $8.25/month.

Whether you’re currently taking naltrexone or just doing some research on alcohol moderation, we’d love to have you sign up for our 15-day free trial today.