How Long Does Naltrexone Last?

Medically Reviewed by Johnelle Smith, M.D. on April 19, 2022

The duration of naltrexone effects vary depending on the formulation taken. Oral naltrexone lasts 24 hours with the average dose. The extended-release form of naltrexone (Vivitrol) releases its effects over a one-month period.

How Long Does Naltrexone Last?

Naltrexone, also known as Revia and Vivitrol, is a prescription medication that can reduce cravings for opiates and alcohol, as well as block their euphoric effects.

The short-acting form of naltrexone (Revia, Depade) can have effects that last 24 hours on average, while long-acting naltrexone (Vivitrol) has effects that last about one month.

How long this medication lasts depends on the formulation taken, the dose taken, and other personal and biological factors.

Read more about using Naltrexone for alcohol and opioid addiction

How Long The Effects Of Oral Naltrexone Last

Oral naltrexone (Revia, Depade) comes in pill form. It is typically directed for use once a day, once every other day, or once every three days.

Average duration of effects, by dosage:

  • 50 milligrams (mg): 24 hours
  • 100 milligrams (mg): 48 hours
  • 150 milligrams (mg): up to 72 hours

The standard dosage of naltrexone for adults is 50 mg once a day. Your doctor may prescribe a higher or lower dosage based on personal health needs.

How Long The Effects Of Injection Naltrexone Last

Vivitrol is an extended-release (long-acting) form of naltrexone that is administered intramuscularly once every four weeks, or once a month.

The effects of Vivitrol peak twice after administration: first, about two hours after administration, and then once more about two to three days after administration.

Concentrations of Vivitrol in the body begin to decline about 14 days after administration in most people. This doesn’t necessarily affect its efficacy, however.

Side effects of Vivitrol, such as nausea or reactions at the injection site, will generally go away within the first few days after receiving Vivitrol.

Get Started On The Road To Recovery.

Get Confidential Help 24/7. Call Today!

(844) 616-3400

What Can Affect How Long Naltrexone Lasts?

How long the effects of a medication last can vary from person to person, depending on how fast the body breaks down the substance in a person’s system.

Factors that can influence this include:

  • age of the person
  • use of other medications
  • metabolic rate
  • liver and kidney function

Certain health conditions, such as liver disease, may affect the metabolism of naltrexone in the body, which can in turn affect the strength and duration of drug effects.

Call Today To Find Naltrexone Treatment Options

Naltrexone is a prescription medication that is proven to help people maintain their sobriety by reducing cravings for alcohol and opioids.

If you’re looking for naltrexone treatment for yourself or a loved one, call our helpline today to find naltrexone treatment options at an addiction rehab center near you.

This page does not provide medical advice. See more

Addiction Resource aims to provide only the most current, accurate information in regards to addiction and addiction treatment, which means we only reference the most credible sources available.

These include peer-reviewed journals, government entities and academic institutions, and leaders in addiction healthcare and advocacy. Learn more about how we safeguard our content by viewing our editorial policy.

  • Was this Helpful?
  • YesNo
Medically Reviewed by
Johnelle Smith, M.D. on April 19, 2022
Let us walk you through the treatment process. We're here to help.
For 24/7 Treatment Help:
100% Free & Confidential. Call (844) 616-3400