What is Vivitrol®️ (extended-release naltrexone)?


Vivitrol® is an injectable, extended-release formulation of naltrexone, an opioid antagonist. The medication is used to treat opioid use disorder (OUD) by preventing relapse after detoxification. By blocking the effects of opioids, Vivitrol helps to reduce cravings and maintain abstinence.

Historical context

Naltrexone was first approved by the FDA in 1984 in tablet form, while the extended-release injectable formulation, Vivitrol, was approved for the treatment of OUD in 2010. It has since become a valuable option in medications for addiction treatment (MAT), offering a once-monthly injection as an alternative to daily medication regimens.

Medical formulations

Vivitrol is available as an injectable suspension for intramuscular use.

How long does Vivitrol stay in your system?

Vivitrol is a long-acting injectable form of naltrexone designed to be administered once a month. The half-life of naltrexone in Vivitrol is approximately 5 to 10 days. It can take about 25 to 50 days for the drug to be completely eliminated from the body after the last injection.

Street names

Vivitrol, Naltrexone shot


Vivitrol is a sterile, milky-white suspension that comes in a single-use vial. The suspension is administered as a gluteal intramuscular injection by a healthcare professional.

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