Naltrexone: How Long Does It Last?3 min read

Welcome, dear reader, to a journey of discovery as we delve into the fascinating realm of naltrexone. Today, we aim to answer a commonly asked question: How long does naltrexone last? Naltrexone, a medication used in the treatment of substance abuse disorders and alcohol addiction, possesses unique properties that contribute to its duration of action. Join us as we explore the intricacies of this medication’s longevity and shed light on its effects within the human body.

Naltrexone and Its Mechanism of Action:

To truly understand the duration of naltrexone’s effects, we must first grasp how it interacts with the body. Naltrexone is an opioid receptor antagonist, meaning it binds to the opioid receptors in the brain and blocks the effects of opioids. By doing so, it helps reduce cravings and prevents the pleasurable sensations associated with drug or alcohol use.

Immediate-Release Naltrexone:

When discussing the duration of naltrexone, it’s important to distinguish between immediate-release and extended-release formulations. Immediate-release naltrexone is typically administered as a daily oral tablet or as an injectable medication. After oral administration, the effects of immediate-release naltrexone are generally felt within one hour and last for approximately 24 hours. However, it’s worth noting that the individual metabolism and response to the medication may vary.

Extended-Release Naltrexone:

Extended-release naltrexone, marketed under the brand name Vivitrol, provides a longer duration of action compared to its immediate-release counterpart. It is administered via a monthly injection, ensuring steady and continuous release of the medication into the body. The extended-release formulation offers the convenience of monthly dosing, reducing the need for daily medication adherence.

Studies have demonstrated that a single dose of extended-release naltrexone can effectively block the effects of opioids for up to four weeks. This extended duration is beneficial for individuals undergoing addiction treatment, as it helps maintain abstinence and reduces the risk of relapse.

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Factors Influencing Naltrexone’s Duration:

Several factors can influence how long naltrexone lasts in the body. One such factor is an individual’s metabolism. Each person metabolizes medications at a different rate, which can impact the duration of naltrexone’s effects. Additionally, factors such as liver function, age, and overall health may play a role in how the body processes and eliminates the medication.

Naltrexone’s Role in Addiction Treatment:

Understanding the duration of naltrexone is essential for optimizing its use in addiction treatment. By providing a sustained blockade of opioid receptors, naltrexone helps individuals overcome cravings and maintain sobriety. It complements other forms of therapy, such as counseling and support groups, by supporting the recovery process and reducing the risk of relapse.

It’s important to note that naltrexone should only be used under the supervision of a qualified healthcare professional. They will determine the appropriate dosage and duration of treatment based on individual needs and response.

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As we conclude our exploration into the longevity of naltrexone, we’ve discovered that the duration of its effects depends on various factors, including the formulation used and individual characteristics. Immediate-release naltrexone typically lasts for approximately 24 hours, while the extended-release formulation can provide up to four weeks of continuous protection against opioid effects. Understanding these durations empowers healthcare providers and individuals undergoing addiction treatment to make informed decisions regarding medication regimens.

Remember, dear reader, naltrexone is just one piece of the puzzle in the journey towards recovery. Combining medication with comprehensive treatment approaches can pave the way to a brighter future, free from the shackles of addiction.


  • Mayo Clinic. (2021). Naltrexone (Oral Route).
  • U.S. National Library of Medicine. (2019). Naltrexone.
  • Substance Abuse and Mental Health Services Administration. (2015). Medication for the Treatment of Alcohol Use Disorder: A Brief Guide.
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