Naltrexone is a medication primarily used in the treatment of opioid dependence and alcohol use disorder. It works by blocking the effects of opioids and alcohol in the brain, reducing cravings and preventing relapse. Naltrexone is available in both oral and extended-release injectable formulations. Additionally, low-dose naltrexone (LDN) is sometimes used off-label for conditions such as autoimmune diseases, chronic pain, and fibromyalgia. Naltrexone should be used under medical supervision, and its effectiveness may vary depending on individual circumstances and adherence to treatment.

Naltrexone 50 mg is a prescription medication used primarily to help people stay off alcohol or opioids after they’ve quit. It works by blocking opioid receptors in the brain, which reduces cravings and prevents any feeling of “high” if opioids or alcohol are consumed.

What is Naltrexone 50 mg?

• Class: Opioid antagonist
• Main use: Supports recovery from opioid or alcohol dependence
• Form: Usually an oral tablet (50 mg), sometimes available as an injection (Vivitrol, monthly)

How It Works

• Blocks the “reward” effect of opioids and alcohol
• Reduces cravings and helps prevent relapse
• Does not cause withdrawal or addiction itself

Common Uses

Typical Dosage

• 50 mg once daily (oral tablet)
• Can also be given as a 380 mg monthly injection (brand: Vivitrol)

Important Warnings

• Do not use if currently taking opioids – may cause sudden withdrawal
• You must be opioid-free for at least 7–10 days before starting
• Not for use in patients with severe liver problems

Side Effects

• Nausea
• Headache
• Fatigue
• Anxiety
• Trouble sleeping
• In rare cases: liver toxicity (requires monitoring)

Good to Know

• Not a cure, but part of a recovery plan including therapy/support
• Doesn’t cause dependence or a “high”
• Must be taken regularly to be effective

1. What is Naltrexone 50 mg used for?
It’s used to help people who have stopped drinking alcohol or using opioids to stay off them. It reduces cravings and prevents the “high” if they relapse.

2. How does Naltrexone 50 mg work?
It blocks opioid receptors in the brain. This stops alcohol or opioids from giving any pleasure, making it easier to avoid relapse.

3. Will Naltrexone make me feel high or sedated?
No. Naltrexone is not addictive and doesn’t cause a high or drowsiness. It works quietly in the background to support recovery.

4. Do I need to stop opioids before taking Naltrexone?
Yes. You must be opioid-free for at least 7–10 days before starting, or it can cause sudden withdrawal symptoms.

5. Can I take Naltrexone while drinking alcohol?
It won’t make you sick like disulfiram (Antabuse), but it reduces the pleasure of drinking, which helps break the habit. It’s meant to be taken after you’ve quit.