Blog | Behavioral Health Group

Naltrexone Explained: Benefits, Side Effects and What to Expect

Written by BHG Author | Jun 24, 2025 11:00:00 AM

When it comes to treating opioid and alcohol use disorders, one FDA-approved medication offers a unique path to recovery: naltrexone. Unlike medications that contain opioids, naltrexone stands out as an option, offering a distinct approach to treatment by helping to reduce cravings and prevent relapse without the risk of dependence or misuse.

But what exactly is naltrexone? How does it work? And is it right for your recovery journey? Here’s everything you need to know about this medication.

What Is Naltrexone?

Naltrexone is an opioid antagonist, meaning it blocks the effects of opioids in the brain. As an opioid antagonist, it helps reduce cravings and prevents opioids from producing their usual ‘high.’ One of the key advantages of naltrexone is that it’s not a controlled substance, and there are no withdrawal symptoms if you stop taking it. It’s part of a broader, evidence-based approach called medication-assisted treatment (MAT), which combines medication with counseling and wraparound services.

Naltrexone comes in two main forms:

  • Extended-release injection (brand name Vivitrol): Administered once a month by a healthcare provider. This form is administered at Behavioral Health Group (BHG) for individuals receiving treatment for opioid use disorder (OUD).
  • Oral tablet: Typically prescribed for alcohol use disorder (AUD). Due to the increased risk of overdose if doses are missed, BHG does not offer the oral formulation for OUD.

At BHG, we prioritize safety and long-term success in recovery. That’s why we use the extended-release injection for OUD treatment - ensuring consistent medication coverage and reducing the risk of relapse or overdose.

How Naltrexone Works

Naltrexone works by targeting the brain's reward system - specifically, the opioid receptors. Whether it’s opioid or alcohol, these substances work to activate cells in the brain that release feel-good chemicals like dopamine. Naltrexone blocks those receptors, preventing opioids from producing their euphoric effects. This helps reduce cravings and prevents relapse by stopping the cycle of reward-seeking behavior.

Think of Naltrexone as a shield. Even if you feel tempted to use opioid or alcohol, the medication stops the substance from having its usual rewarding effect on your brain. Over time, this helps break the cycle of reward-seeking behavior that drives addiction and supports long-term recovery.

Before starting Naltrexone, you’ll need to be free from opioids for 7–10 days. Taking the medication too soon may lead to withdrawal symptoms. Your healthcare provider will guide you through a safe and supported process before beginning treatment.

Potential Side Effects of Naltrexone: What You Need to Know

Like most medications, Naltrexone can cause side effects. The good news is that most are mild and temporary, especially as your body adjusts. Still, it's important to be aware of both common and more serious side effects, and when to contact your healthcare provider.

Common Side Effects

  • Headache
  • Nausea or vomiting
  • Cold-like symptoms
  • Decreased appetite
  • Dizziness or drowsiness

Serious Side Effects

  • Severe reactions at the injection site (redness, swelling, pain)
  • Liver damage (especially with high doses or in individuals with liver conditions)
  • Pneumonia
  • Mood changes, including depression or thoughts of self-harm

If you experience any symptoms that feel unusual or concerning, contact your healthcare provider right away.  It’s always better to check in early and stay ahead of any potential complications. For urgent or severe reactions - like difficulty breathing or signs of a severe allergic reaction, call 911 immediately.

Who Should Avoid Naltrexone

While naltrexone is safe for many people, it’s not the ideal medication for everyone. You should avoid naltrexone if:

  • You have not been completely opioid free for at least 7-10 days
  • You have severe liver disease or abnormal liver function

Everyone’s recovery journey is unique and Naltrexone can affect people differently based on individual health and medical history. That’s why it’s important to work closely with your provider to monitor your progress and adjust treatment as needed. Most importantly, working with your provider can ensure this medication is a safe and effective fit for you. 

Benefits of Naltrexone

Naltrexone offers a range of powerful benefits that can support you throughout your recovery. It’s designed to help individuals stay focused, reduce cravings and reduce the risk of relapse. Here's how it can make a difference in your recovery process:

  • No risk of physical dependence: Naltrexone does not cause withdrawal symptoms if stopped and is not associated with misuse or addiction.
  • Reduces cravings: It helps minimize the urge to use by interrupting the brain’s reward response.
  • Blocks opioid effects: By blocking the effects of opioids (and alcohol in other cases), it removes the ‘high’ that fuels substance use, lowering the risk of relapse.
  • Convenient options: Naltrexone is available as a once-monthly injection (used at BHG for OUD) and a once-daily oral pill (typically prescribed for AUD).
  • Clinically proven: Naltrexone is backed by research showing significant improvements in recovery outcomes.

Explore Naltrexone Treatment for Opioid Use Disorder at BHG

Recovery is a path worth taking and you don’t have to walk it alone. At BHG, we provide support for opioid use disorder (OUD) all in one place—offering Naltrexone treatment as part of our comprehensive, evidence-based care model, coupled with counseling, case management and other wraparound services. As one of only 4% of programs nationwide offering all FDA-approved medications, we give you the flexibility to find the approach that works best for you, so you can move forward with confidence.

If you or a loved one is ready to start recovery or needs help now, give us a call at 844-535-7291 or find a BHG location near you.

If you’re a healthcare provider or a referring partner, please call our dedicated referral line at 866-763-2244 or submit an online referral form on our website. We’re here to help guide you every step of the way.

 

 

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