Vivitrol is the extended-release injectable form of naltrexone. Here's how it differs from oral naltrexone, who it's for, and what the research shows.
Educational Information Only
Not a substitute for medical advice. Always consult a licensed clinician.
If you have been researching naltrexone for alcohol use disorder, you have probably encountered two forms: a daily oral tablet (50mg) and an extended-release injectable called Vivitrol. Both contain the same active ingredient — naltrexone — but they work differently, are used in different contexts, and have meaningfully different implications for the Sinclair Method.
Vivitrol is the brand name for extended-release injectable naltrexone (XR-NTX). It is a monthly intramuscular injection that delivers naltrexone slowly over approximately 30 days, maintaining a consistent blood level of the medication throughout the month. It was FDA-approved for alcohol use disorder in 2006 and for opioid use disorder in 2010.
The injection is administered by a healthcare provider, typically in a clinical setting. It cannot be self-administered.
| Feature | Oral Naltrexone (50mg tablet) | Vivitrol (XR-NTX injection) |
|---|---|---|
| Administration | Daily oral tablet | Monthly injection by clinician |
| Adherence | Requires daily self-administration | Administered once monthly; no daily pill |
| Blood levels | Variable; depends on daily dosing | Consistent sustained release over 30 days |
| Sinclair Method compatible? | Yes — taken before drinking | No — constant blood levels prevent targeted use |
| Cost | Low (generic available) | High (~$1,500/month without insurance) |
| Insurance coverage | Usually covered | Often covered with prior authorization |
| Requires abstinence before starting? | No (for alcohol) | Yes — typically 7-10 days abstinence recommended |
This is the most important distinction for people researching the Sinclair Method: Vivitrol is not compatible with the Sinclair Method protocol.
The Sinclair Method requires naltrexone to be taken specifically before drinking — so that the medication is active during the drinking experience, allowing pharmacological extinction to occur. Vivitrol maintains a constant blood level of naltrexone 24 hours a day, 7 days a week, regardless of whether you are drinking. This means it cannot be used in the targeted, pre-drinking protocol that defines TSM.
Vivitrol is primarily designed to support abstinence — by ensuring that naltrexone is always present, it reduces the reward of any drinking that occurs and supports people who are committed to not drinking at all. It is particularly useful for people who struggle with medication adherence, since there is no daily pill to remember or forget.
Vivitrol may be appropriate for:
Vivitrol is generally not the right choice for people who want to use the Sinclair Method, reduce drinking gradually, or maintain any drinking while on medication.
The pivotal clinical trial for Vivitrol in alcohol use disorder (Garbutt et al., 2005, JAMA) enrolled 627 patients and found that the 380mg dose significantly reduced heavy drinking days compared to placebo (25% reduction vs. 10%). The 190mg dose did not show a significant difference. The medication was generally well-tolerated, with injection site reactions and nausea as the most common side effects.
As always, the right medication and protocol depends on your individual situation, goals, and medical history. Speak with a licensed clinician before making any decisions about treatment.