Vivitrol (Extended-Release Injectable Naltrexone)
Vivitrol is a once-monthly injection that blocks opioids and quiets alcohol cravings. Here's how the shot differs from the daily pill, the detox-first rule you can't skip, and who it fits best.
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What Vivitrol Is
Vivitrol is the brand name for extended-release injectable naltrexone — a single shot of long-acting medication given into the muscle once a month. The same drug exists as a daily pill, but Vivitrol packs a full month of naltrexone into one injection, so there is no pill to remember. It is approved for both opioid use disorder and alcohol use disorder, which makes it one of the few medications that works across two of the hardest addictions to treat.
What sets Vivitrol apart from methadone or buprenorphine is what it does at the receptor. It is a blocker, not a substitute — it occupies the brain’s opioid receptors and shuts the door, rather than gently filling them the way an opioid medication does. That single fact shapes everything about how it is used, who it fits, and the one safety rule you cannot skip: you have to be fully off opioids before the first shot. None of that is a reason for fear. It is a real, evidence-backed path out, and for the right person it works.
Starting Vivitrol, or just stopped it? Read this first. Call 988 any time you're in danger.
What to do:
- Don’t take the first shot until you’re fully detoxed from opioids. Naltrexone given too soon throws you into sudden, severe withdrawal. The standard rule is roughly 7 to 10 days opioid-free before your first injection[1]. A treatment team manages this safely so you don’t have to guess. Find a detox or treatment program →
- If you stopped Vivitrol or missed a shot, your overdose risk goes up — not down. The block fades, your tolerance is already gone, and a dose you once handled can now be fatal. Overdose is the leading cause of death in the high-risk weeks after people lose that protection[2][3]. Never use alone, and keep naloxone nearby.
- If someone has overdosed (slow or stopped breathing, can’t be woken), call 911 and give naloxone.
- One shot covers a month: injected into the muscle, naltrexone blocks opioid receptors for roughly 30 days, removing the daily decision that trips up pill-based treatment[4].
- It treats two addictions: Vivitrol is used for both opioid use disorder and alcohol use disorder, and in head-to-head opioid trials it performs comparably to buprenorphine[5].
- You must be opioid-free first: the standard practice is a 7- to 10-day washout after the last opioid before the first injection, because giving it too soon triggers precipitated withdrawal[1].
- It blocks the high and the overdose: because naltrexone is a pure blocker, it has no euphoria and no street value, and it blunts both the rewarding and the overdose effects of opioids[4].
- The biggest gain is sticking with it: the whole point of the monthly shot is adherence, since relapse after stopping daily medication is common[6].
How Vivitrol Is Different from the Naltrexone Pill
Vivitrol and the oral pill are the same medicine, delivered two ways. The drug is naltrexone in both, and the way it works in the brain is identical: it blocks opioid receptors so that opioids and alcohol lose their reward. If you want the full mechanism, the deeper naltrexone explainer covers how the receptor blockade reduces drinking and craving. The story specific to Vivitrol is everything that changes when you turn a daily pill into a once-a-month injection.
The difference that matters most is adherence. A daily pill only protects you on the days you actually take it, and missing a stretch of doses leaves a gap exactly when relapse is most likely. Medication discontinuation is one of the central reasons treatment fails — relapse rates run high once people stop taking what was prescribed[6]. A monthly shot removes that daily test of willpower entirely. The improved adherence of a long-acting injection is the main reason clinicians reach for it[6].
Real-world data show how lopsidedly the two forms get used. In a large analysis of veterans starting medication for alcohol use disorder, more than 25,000 began oral naltrexone while only a few hundred started the extended-release injection[7]. The injection is recommended yet underused — not because it works less well, but because of cost, access, and the fact that it has to be given in a clinic.
| Vivitrol (injection) | Oral naltrexone (pill) | |
|---|---|---|
| Dose | One shot into muscle, monthly | One tablet, daily |
| What you have to do | Show up once a month | Decide to take it every day |
| Coverage | Steady block for about 30 days[4] | Only on days you take it |
| Main advantage | Adherence is built in[6] | Easy to start and stop |
| Opioid washout first? | Yes, 7 to 10 days[1] | Yes |
Neither form is “better” in the abstract. The pill is simpler to start and easy to stop; the injection carries you through the month whether or not motivation holds that day. For someone whose history is a string of good intentions broken by missed doses, that structural difference is the whole point.
Why Vivitrol Is a Blocker, Not a Substitute
This is where Vivitrol parts ways with the two medications most people have heard of. Methadone and buprenorphine are agonists — they activate the opioid receptor, satisfy the body’s expectation of an opioid, and in doing so calm withdrawal and craving. Naltrexone is the opposite. It is an antagonist: it sits on the receptor and blocks it, activating nothing[4].
That difference cuts two ways, and being clear-eyed about both is what makes Vivitrol the right tool for some people and the wrong one for others.
The upside of being a blocker. Because naltrexone activates nothing, it produces no high, causes no physical dependence, and has no street value. There is nothing to misuse and nothing to divert[4]. While the block is active, opioids simply do not work; the euphoria they would normally produce is shut off[4]. For someone determined to stay completely opioid-free, that is exactly the help they want — a wall between them and a relapse.
The trade-off. A blocker gives no relief from withdrawal or craving the way an agonist does, because it is doing nothing at the receptor except holding the door shut. That is the central reason you must be detoxed before starting, and it is also why staying in treatment can be harder than with buprenorphine or methadone — there is no soothing effect pulling you back for the next dose, only your own resolve and your support system. Even so, the evidence is encouraging: in head-to-head randomized trials for opioid use disorder, once people are actually started on it, extended-release naltrexone performs comparably to buprenorphine[5].
The Detox-First Rule You Cannot Skip
If there is one thing to carry away, it is this. You have to be fully off opioids before your first Vivitrol shot. Get this wrong and the result is not a minor side effect. It is sudden, severe, precipitated withdrawal.
Here is the mechanism in plain language. Naltrexone binds opioid receptors very tightly. If opioids are still present when the injection goes in, the naltrexone displaces them from the receptors in one stroke, and the brain crashes into withdrawal far faster and harder than it would on its own. Unlike ordinary withdrawal, you cannot ease it by taking an opioid — the receptors are blocked for weeks.
That is why the prescribing instructions build in a washout period. Standard practice is a 7- to 10-day opioid-free window before the first injection; when someone is coming off methadone or buprenorphine, the typical approach is a taper followed by that washout, often during a 10- to 15-day inpatient stay[1]. The need to get through withdrawal before you can even start is the single biggest barrier to using this medication[8].
The hopeful part is that medicine has gotten much better at carrying people across this gap. Newer rapid-induction protocols use very low doses of oral naltrexone alongside non-opioid comfort medications to shorten the runway to about 5 to 7 days[1]. Others bridge the transition with a structured buprenorphine taper before moving to the injection[9]. The washout is a real hurdle — but it is a managed, time-limited one, not the agony people picture, and a treatment team exists precisely to get you through it safely. Find a program that handles the transition →
The Overdose Risk After You Stop
Vivitrol protects you while it is working. The danger comes at the other end — when it wears off, gets missed, or gets stopped.
While the block is active, opioids can’t reach the receptor, so the body’s tolerance to opioids quietly fades. That is fine as long as the medication is on board. But if someone stops Vivitrol and returns to opioids, especially at the dose they used before, their body can no longer handle it, and an amount they once tolerated can stop their breathing. This is the same lost-tolerance trap that makes the period after any break in opioid use so deadly.
The data on this are sobering. Overdose is the leading cause of death in the weeks after people leave settings where they were opioid-free, and in the first two weeks after release from incarceration the risk of fatal overdose runs more than twelve times higher than in the general population[2]. Extended-release naltrexone is used in exactly these high-risk windows because a single shot delivers about 30 days of overdose protection[3] — but that protection ends when the medication does.
This is not a reason to avoid Vivitrol — it is a reason to never stop it without a plan. If you and your clinician decide to come off it, that decision deserves the same care as starting it: a step-down strategy, continued counseling, naloxone within reach, and the firm rule that you never use alone. A return to opioids after a period of protection is a medical emergency waiting to happen, and it is entirely survivable when you see it coming.
What Vivitrol Does for Opioid Use Disorder
For opioid use disorder, Vivitrol is the monthly injection that keeps the door to opioids closed. Once you are detoxed and started, the medication blocks the euphoric and the overdose effects of opioids for about a month at a time[4], which means a moment of weakness doesn’t have to become a relapse — the drug simply won’t deliver what the craving is chasing.
The evidence base here is real. Extended-release naltrexone is an established, evidence-based treatment for opioid use disorder, and in direct comparisons it holds its own against buprenorphine[5]. The published reviews that put Vivitrol on the map looked specifically at how successfully people get started on it, how well they stick with it, and whether it actually reduces opioid use — the three questions that decide whether any opioid medication is worth using[10].
Vivitrol is not the only effective choice, and it is not automatically the best one. Because it offers no relief from craving the way an agonist does, some people find it harder to stay on — which is why the honest move is to weigh it against the alternatives rather than treat any single medication as the answer. If a clinic offers only Vivitrol, it is fair to ask about buprenorphine and methadone too, so the choice fits you.
What Vivitrol Does for Alcohol Use Disorder
Vivitrol’s second job is treating alcohol use disorder, a condition that affects more than 28 million people in the United States and drives enormous harm[11]. Worldwide, alcohol is tied to more than 3.3 million deaths a year — close to 5% of all deaths[12]. Medication is one of the most effective and most underused tools against it.
The way naltrexone helps with drinking is the same receptor blockade described on the naltrexone page: it blunts the reward alcohol produces, so drinking becomes less reinforcing and craving eases. What the injectable form adds is, again, consistency. Alcohol treatment is repeatedly undone by people stopping their medication — relapse rates after seeking treatment have been measured as high as 39% — and the long-acting injection exists specifically to improve that adherence[6].
Vivitrol carries an official endorsement for this use. Department of Veterans Affairs and Department of Defense clinical guidelines recommend extended-release naltrexone as a treatment option for moderate-to-severe alcohol use disorder[13]. The catch is the gap between recommendation and practice: in the VA system, oral naltrexone is started far more often than the injection, despite both being recommended[7]. If you have struggled to keep up with a daily pill for drinking, the monthly shot is a legitimate option worth raising with your prescriber — and, unlike with opioids, you do not need an opioid washout for alcohol treatment unless you are also using opioids.
Who Vivitrol Fits Best
Vivitrol is at its strongest for people who are past detox and highly motivated, set on staying completely abstinent, and helped by structure. Because it offers no high and no withdrawal relief, it works best when the goal is a clean break rather than a gradual one, and when the daily-pill approach has already proven hard to sustain.
A few situations where it tends to shine:
- People who keep missing daily doses. If a daily pill has failed not for lack of wanting but for the sheer relentlessness of taking it, the monthly injection removes the exact point of failure[6].
- People leaving controlled settings. The weeks after leaving jail, prison, or inpatient treatment are when overdose risk spikes[2], and a single shot covers roughly the first month of that window with overdose protection[3].
- Criminal-justice and supervised treatment settings. Naltrexone is often more accessible than methadone or buprenorphine in justice settings, where agonist medications can be hard to obtain, and it has been studied closely in this population[14][15].
That last point comes with an honest caveat. In many justice settings Vivitrol is offered partly because, as a non-addictive blocker, it sidesteps the stigma and regulatory hurdles that agonist medications face[14]. When people in these settings have been asked, their views on the available options — Vivitrol, methadone, buprenorphine, or none — vary widely[16]. A genuine choice means being told about every evidence-based option, not just the one a program happens to offer. And the goal of treatment is a real life, not just compliance: extended-release naltrexone has been studied for its effect on quality of life and retention precisely because feeling better, not merely abstaining, is what keeps people in recovery[17].
Side Effects and Safety
Vivitrol is generally well tolerated, and most of its side effects are mild and fade. The two worth understanding in advance are injection-site reactions and the old liver warning.
Injection-site reactions are the most common complaint, since this is a thick, long-acting depot delivered deep into muscle. Expect possible pain, tenderness, firmness, or bruising where the shot goes in; these usually settle on their own. Rarely, more serious site reactions can occur, which is why the injection is given by a trained clinician and the sites are rotated.
The liver question deserves a clear answer, because it scares people off needlessly. Naltrexone once carried a black-box warning for liver toxicity, and that warning has limited its use[18]. The actual evidence at normal doses is reassuring. In a randomized trial, people who received extended-release naltrexone showed no signal of liver injury compared with those who got placebo — the injection was not linked to hepatotoxicity[18]. Naltrexone has even been examined and found usable in people with cirrhosis, a group once assumed to be off-limits[19]. Sensible liver monitoring is still appropriate, but for most people the old warning should not be the reason to walk away from an effective medication.
Pain control while on Vivitrol takes some planning. Because the medication blocks opioid receptors, standard opioid painkillers won’t work normally while it is active — important if you face surgery or an injury. Tell every provider you are on naltrexone, and carry something that says so, so your care team can plan non-opioid pain control in advance.
Cost and Getting Access
The honest downside of Vivitrol is cost. The injection is far more expensive than the generic pill, and that price has been a genuine barrier to its use — even in prison and jail systems where it could save lives, the upfront cost has slowed adoption[3]. That expense is one reason the much cheaper oral pill is started so much more often[7].
None of that means the shot is out of reach. Most insurance, Medicaid, and Medicare plans cover it, though they often require prior authorization, and the manufacturer and many public programs offer assistance that can lower or erase the out-of-pocket cost. The practical move is to treat cost as a question to ask openly. What will this actually cost me, and what help is available? That beats letting a price tag quietly rule it out before you’ve explored it.
Vivitrol Works Best as Part of a Plan
Vivitrol is a powerful tool, but it is a tool, not a cure on its own. It works best woven into real support — counseling, a recovery community, and a clinician who knows your history. The medication holds the door shut; the rest of the plan is what helps you build the life that makes you want to keep it closed. The point of treatment was never just to stop using. It is the quality of life and the staying-in-recovery that the medication is meant to protect[17].
If you are weighing your options, it is worth seeing the whole menu. Compare the blocker approach here with the agonist medications — buprenorphine and methadone — and read the deeper naltrexone overview to understand the shared mechanism. Whichever path fits, the most important step is the next one.
Find treatment that fits your life →
The next step doesn’t have to be a big one. You can find treatment now and get matched with someone who can help you find the right care and take the next step. Reaching out today is a real step forward — and one you can make right now.
Frequently asked questions
What is Vivitrol and how is it different from the naltrexone pill?
Vivitrol is the brand name for extended-release injectable naltrexone, a once-monthly shot given into the muscle that blocks opioid receptors for about 30 days[4]. It contains the same medication as the daily naltrexone pill and works the same way in the brain, so the real difference is delivery. The injection removes the daily decision to take a pill, which is its main advantage, since relapse rates are high once people stop taking a daily medication[6].
Why do you have to be off opioids before starting Vivitrol?
Naltrexone binds opioid receptors tightly, so if opioids are still in your system when the shot is given, it displaces them all at once and triggers sudden, severe precipitated withdrawal. To prevent that, standard practice is a 7- to 10-day opioid-free washout before the first injection, often with a methadone or buprenorphine taper beforehand during an inpatient stay[1]. Needing to get through withdrawal before you can even start is the biggest barrier to using the medication, which is why a treatment team manages the timing[8].
Does Vivitrol treat both opioid and alcohol addiction?
Yes. Vivitrol is used for both opioid use disorder and alcohol use disorder[5]. For opioids it blocks the euphoric and overdose effects of any opioid taken[4], and for alcohol it blunts the reward of drinking so cravings ease. Department of Veterans Affairs and Department of Defense guidelines recommend extended-release naltrexone as a treatment option for moderate-to-severe alcohol use disorder[13].
Is Vivitrol addictive or can it be misused?
No. Naltrexone is an antagonist, meaning it blocks opioid receptors without activating them, so it produces no high, causes no physical dependence, and has no street value[4]. That is the opposite of agonist medications like methadone and buprenorphine, which activate the receptor to ease withdrawal and craving. The trade-off is that a blocker gives no relief from craving, which is part of why being detoxed first matters so much.
Why is overdose risk higher after stopping Vivitrol?
While the shot is active, your tolerance to opioids fades because opioids can’t reach the receptor. If you stop the medication and return to opioids at your old dose, your body can no longer handle it and the same amount can be fatal. Overdose is the leading cause of death in high-risk windows after people lose that protection, with fatal-overdose risk in the first two weeks after release from incarceration running more than twelve times the general rate[2]. A single injection gives about 30 days of overdose protection, but that protection ends when the medication does[3].
Is Vivitrol safe for your liver?
For most people, yes. Naltrexone once carried a black-box warning for liver toxicity that has limited its use, but that warning came from very high doses[18]. In a randomized trial, people who got extended-release naltrexone showed no liver injury compared with placebo, so the injection was not linked to hepatotoxicity at treatment doses[18]. It has even been studied and found usable in people with cirrhosis[19]. Routine liver monitoring is still sensible, but the old warning is rarely a reason to refuse the medication.
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