Vivitrol is naltrexone. Specifically, Vivitrol is the brand name for the monthly intramuscular injection form of naltrexone. The daily pill form (sold as ReVia or generic naltrexone) and Vivitrol contain the same active medication — the difference is the formulation, the dosing interval, and how it’s given.
What is the difference between naltrexone and Vivitrol?
Both contain naltrexone, an opioid antagonist. Generic oral naltrexone is commonly used for alcohol use disorder and opioid blockade. Vivitrol is the extended-release injectable form FDA-approved for alcohol dependence and for prevention of return to use of opioid dependence after detoxification.
- Oral naltrexone: generic 50 mg tablet, historically known by the discontinued brand name ReVia. Typically taken once daily by mouth.
- Vivitrol: a 380 mg extended-release injection given into the gluteal muscle once a month by a healthcare provider.
Vivitrol is naltrexone in a slow-release form — the same drug, packaged for monthly dosing instead of daily.
How do they compare?
| Feature | Oral naltrexone | Vivitrol (injection) |
|---|---|---|
| Active medication | Naltrexone | Naltrexone |
| How it’s taken | Daily pill | Monthly intramuscular injection |
| Who administers it | Self at home | Healthcare provider in clinic |
| Adherence requirement | Daily decision | One decision per month |
| Typical cost without insurance | Lower (generic available) | Significantly higher |
| Telehealth-only | Pill can sometimes be prescribed by telehealth where legally permitted | Requires in-person visit for the injection |
| Overdose risk after stopping | Yes — opioid tolerance may be lower after stopping or missed doses | Yes — especially near end of dosing interval, after a missed dose, or after stopping |
Who fits each?
Oral naltrexone may be the better fit when:
- You can reliably remember a daily dose
- Cost is a barrier (generic pills are much cheaper than the injection)
- You want the option to stop quickly if needed (the medication clears in days)
Vivitrol may be the better fit when:
- Daily dosing has been a challenge in the past
- You have a stable schedule that allows monthly clinic visits
- The cost is covered by insurance or a patient-assistance program
Both require an opioid-free period before starting
Whether daily or monthly, naltrexone requires a multi-day opioid-free interval before starting. Per Vivitrol labeling: at least 7–10 days off short-acting opioids; longer (often up to about 2 weeks) after methadone, buprenorphine, or other long-acting opioids. Starting too soon causes precipitated withdrawal — sudden, intense, and difficult to reverse.
There is no completely reliable way to know that every patient has had an adequate opioid-free interval; some clinicians use toxicology testing, clinical assessment, or a naloxone challenge when appropriate. Naltrexone labeling notes that no completely reliable method exists for determining whether a patient has had an adequate opioid-free period.
Once Vivitrol is given, the medication cannot simply be removed or stopped the way a pill can, and its antagonist effect persists across the monthly dosing interval — so precipitated withdrawal after a Vivitrol injection is harder to manage than after an oral dose.
How much does Vivitrol cost?
Vivitrol is usually much more expensive than generic oral naltrexone. Actual cost depends on insurance, pharmacy or clinic billing, administration fees, manufacturer assistance, and site of care. Eligible patients may qualify for manufacturer (Alkermes) co-pay savings, subject to eligibility limits — ask the clinic that administers the injection about whether they participate.
Generic oral naltrexone is widely available and substantially less expensive than Vivitrol; check your local pharmacy or a discount program for a current cash price.
