Written by Healing Sky Editorial Team. Clinically reviewed by Cynthia Abraham D.O.
The first weeks and months after stopping opioids are the most dangerous. Cravings surge, stress mounts, and even small triggers can reopen the door to use. Vivitrol, the extended-release once-monthly injectable form of naltrexone, is one evidence-based medication for opioid use disorder (MOUD) that lowers relapse and overdose risk during this window. This guide explains how it works, who it helps most, how to prepare for the first injection, and what to expect through maintenance.
Opioid use disorder is a chronic, relapsing brain condition, not a moral failing. Medications for opioid use disorder are a standard part of treatment, and Vivitrol is a non-addictive option for people who have completed detox and want ongoing protection.
Vivitrol contains naltrexone, a pure opioid antagonist that sits on the brain's mu-opioid receptors without activating them. If someone uses opioids while Vivitrol is active, those receptors are blocked, so the drug's euphoria and reinforcing effects do not occur. This breaks the cycle of "use, feel better, use again" that drives relapse.
Unlike methadone (a full agonist) or buprenorphine (a partial agonist), naltrexone has no opioid effect and is not habit-forming. It does not cause physical dependence, and stopping it does not produce opioid withdrawal. Each injection slowly releases medication for about 4 weeks, providing steady protection without the daily decision fatigue of pills.
Many patients also report fewer cravings once on a stable schedule. Craving relief is variable, some feel a strong reduction, others modest, but for many, knowing that opioids will not work while they are protected is stabilizing.
Vivitrol can be used by adults with opioid use disorder who have completed detox and want medication support to prevent relapse. It is worth considering for people who want a non-opioid, non-addictive maintenance option; who prefer monthly injections over daily medication; who have struggled with adherence to oral naltrexone or other treatments; or who have occupational, legal, or personal reasons to avoid opioid-agonist therapy. Motivation, a stable living situation, and supportive people nearby all improve outcomes. For individuals with both alcohol use disorder and opioid use disorder, Vivitrol may address both conditions at once.
Vivitrol is not suitable, or requires careful monitoring, in several situations. Current physiologic dependence on opioids or active withdrawal is a contraindication, as is recent opioid use: short-acting opioids within roughly 7 to 10 days, or long-acting opioids, buprenorphine, or methadone within a longer interval (often 10 to 14 days or more for methadone). Acute hepatitis or liver failure rules it out, and elevated liver enzymes require a clear plan to monitor and manage them. A history of severe injection-site reactions or allergy to naltrexone or the diluent is also a contraindication.
Pregnancy requires special consideration. Data on Vivitrol during pregnancy are limited, and other MOUD may be preferred. Unmanaged major depression or suicidality requires close follow-up during treatment, as mood symptoms must be monitored carefully.
If there is any uncertainty about whether opioids are fully cleared, do not guess. Work with a clinician to verify readiness and avoid precipitated withdrawal.
Complete opioid abstinence is required before starting Vivitrol. That includes heroin, fentanyl, oxycodone, hydrocodone, morphine, codeine cough syrup, and opioid pain pills. For people coming off methadone or buprenorphine, a longer washout is typically needed, with supportive non-opioid medications for sleep, anxiety, muscle aches, and nausea to maintain comfort during that period.
A typical pre-injection visit includes a review of the detox timeline and current symptoms, a urine drug test to confirm absence of opioids, a brief physical exam and baseline labs (often including liver function tests), a pregnancy test for those of childbearing potential, a discussion of risks, benefits, overdose prevention, and a plan for future pain care, and issuing or renewing a naloxone rescue kit for the patient and household. Some clinics use a small oral naltrexone test dose if there is uncertainty about recent opioid exposure. If any withdrawal begins, the process stops and supportive care continues until the patient is ready.
Vivitrol is given as a deep intramuscular injection in the gluteal muscle, alternating sides each month. The medication is thick; the shot can sting or feel sore for a day or two, though most people return to normal activities immediately. The opioid blockade begins within hours and typically lasts about 4 weeks. Cravings often decrease during the first one to two weeks. Mild side effects, fatigue, headache, injection-site soreness, are common and usually fade quickly. The next appointment is scheduled before leaving, at about 28 days. Staying on schedule matters; gaps between doses raise relapse risk.
Consistent follow-up is essential. At each monthly visit, four areas are reviewed: medication effect, mood and sleep, substance use, and safety.
On medication effect, the clinician checks for breakthrough cravings, side effects, and whether the benefit seems to wear off before week 4. Mood and sleep are tracked because depression and anxiety commonly accompany opioid use disorder, and early changes warrant prompt attention. Urine testing is standard at each visit, both to confirm protection and to identify other substances that may be present, such as alcohol, stimulants, or benzodiazepines. Safety review covers overdose prevention, the naloxone kit, and pain-management planning.
Most patients remain on Vivitrol for at least 6 to 12 months. Many continue longer, especially when high-risk triggers are still present or the medication is providing strong support. There is no fixed endpoint; decisions are individualized based on stability, housing, work or school progress, legal or family considerations, and patient preference.
Extended-release naltrexone reduces opioid use and improves abstinence rates compared with counseling alone. People who complete detox and receive their first injection generally experience fewer relapses during active treatment. A critical nuance: getting through the detox and opioid-free window is the hardest part. That early hurdle explains why some programs see lower overall initiation rates compared with buprenorphine or methadone, which can be started while opioids are still in the body.
The practical point is this: if a patient can reach the first injection, the odds of staying opioid-free improve while on schedule. That is why supported detox, frequent contact during the washout, and rapid access for the first dose are priorities.
All three are evidence-based MOUD. The best choice is the one a patient can start, stick with, and feel safe using. Vivitrol blocks receptors (antagonist); buprenorphine is a partial agonist; methadone is a full agonist. Vivitrol is not addictive and stopping it does not cause opioid withdrawal, whereas buprenorphine and methadone create physiologic dependence, not a clinical problem in itself, but important to understand. Vivitrol requires complete opioid abstinence before initiation; the others do not. Some patients stay in treatment longer on agonist medications, particularly those who struggle to complete detox. Vivitrol's monthly dosing can appeal to people who prefer no controlled substances in their body.
Choosing between them involves mapping a patient's history: what has and has not worked before, and what the biggest barriers are right now, cravings, logistics, stigma, or legal constraints. Treatment that aligns with a patient's values and daily life is more likely to be sustained.
Most people tolerate Vivitrol well, and side effects tend to be mild and short-lived. Common effects include injection-site soreness, swelling, or bruising; nausea, upset stomach, or decreased appetite; headache, dizziness, or fatigue; trouble sleeping or vivid dreams; and mild anxiety or irritability.
Less common but important reactions include allergic responses (rash, swelling, breathing problems), liver irritation (right-upper-abdominal pain, dark urine, yellowing of eyes or skin, severe fatigue), and injection-site reactions that worsen, harden, or become very painful.
Seek urgent care immediately for any of the following:
Call a clinician promptly for any persistent or severe symptoms that do not meet the threshold above.
Two overdose scenarios are preventable with planning. The first is trying to break through the blockade: taking large amounts of opioids to overcome Vivitrol can cause respiratory arrest, especially when combined with alcohol, benzodiazepines, or sedatives. The second is loss of tolerance after stopping opioids. While protected by Vivitrol, tolerance drops to a very low level. If a dose is missed, treatment stops, or the blockade wears off after about 4 weeks, even a previously typical amount can be lethal.
Every patient and household member should carry naloxone and know how to use it. Mixing substances, especially alcohol, benzodiazepines, and sedatives, should be avoided. If a slip occurs, the clinician should be contacted immediately rather than waiting for the next scheduled appointment. Wearing a medical alert or carrying a wallet card noting naltrexone use helps emergency teams plan pain control safely.
Because Vivitrol blocks opioid receptors, standard opioid pain medicines will not work reliably. Every provider involved in any procedure or injury care must be told the patient is on extended-release naltrexone. Non-opioid medications, acetaminophen, NSAIDs when safe, certain nerve-pain agents, are the first line. Local, regional, or neuraxial anesthesia is appropriate for procedures. Non-medication strategies such as ice, heat, physical therapy, splinting, and relaxation techniques are also options. If opioids are absolutely necessary, they must be given in a monitored setting with experienced clinicians, because unusually high doses may be required and the risk of respiratory depression rises abruptly as the blockade wanes.
For elective surgery, the timing of injections should be discussed with the surgeon and prescribing clinician in advance.
Naltrexone is processed by the liver. People with acute hepatitis or liver failure should not receive it. For stable chronic hepatitis or past enzyme elevations, treatment can usually continue with close monitoring and patient education about warning signs.
Depression and anxiety commonly accompany opioid use disorder. Vivitrol does not treat these directly, and if mood symptoms worsen, the clinician should be told promptly so therapy or additional treatment can be adjusted.
Data on Vivitrol during pregnancy are limited. Many experts prefer buprenorphine during pregnancy because of its safety profile and ability to prevent withdrawal, which can stress the fetus. If pregnancy occurs while on Vivitrol, a visit should be scheduled promptly to review options and risks.
Vivitrol is typically covered by many commercial plans and Medicaid with prior authorization. Costs vary depending on coverage and copays, and clinics often assist with insurance paperwork, renewals, and patient assistance programs. Starting the authorization process before detox, if possible, reduces delays. Keeping the pharmacy and clinic updated on insurance changes and booking the next appointment at the time of each injection helps avoid schedule gaps.
Medication works best inside a full recovery plan. Evidence-based therapy, cognitive behavioral therapy or relapse-prevention counseling, addresses the patterns and triggers that medication alone cannot reach. Contingency management and other reward-based approaches add further support when available. Peer support through mutual-help groups or recovery coaching, chosen to fit a patient's beliefs and goals, provides community. Practical structure, stable sleep, regular meals, exercise, and consistent daily activities, reduces the ambient stress that drives relapse. Housing stability, vocational help, and legal guidance address the external pressures that undermine recovery.
Relapse risk is highest when protection lapses. If a dose is missed, the injection should be obtained as soon as possible rather than waiting for the next calendar month. If more than 4 to 5 weeks have passed, urine testing and overdose-prevention planning should be revisited before the next injection.
If stopping Vivitrol is the goal, a dedicated visit should be scheduled to discuss timing, supports, and alternatives such as switching to buprenorphine. Overdose risk should be reviewed thoroughly, and naloxone should remain on hand. Stepped-down support, increased counseling frequency, more frequent check-ins, and concrete safety plans for high-risk situations, reduces the danger of the transition period.
Will Vivitrol show up on a drug test? No. Naltrexone is not an opioid and typically does not trigger positive opioid results on standard tests.
Can someone drink alcohol on Vivitrol? Vivitrol is also approved for alcohol use disorder and may reduce drinking, but combining alcohol with any sedatives carries risk. If alcohol is part of the recovery goals being addressed, that should be built into the treatment plan.
What if cravings persist on Vivitrol? The clinician should be told. Targeted therapy can be added, injection timing can be adjusted, and underlying contributors such as sleep problems, pain, or anxiety can be addressed.
Is the first injection the hardest part? The hardest step is usually the detox window leading up to it. With coordinated support, most patients tolerate the injection itself well.
Can Vivitrol treat fentanyl use? Yes. Fentanyl is an opioid and Vivitrol blocks its effects. The same opioid-free requirement before starting applies, and overdose-prevention counseling is especially important given fentanyl's potency.
Healing Sky matches people to providers who offer evidence-based care for opioid use disorder, including Vivitrol maintenance. Through Healing Sky, patients can connect with a provider who coordinates detox and the opioid-free window, integrates therapy and medication management, and provides ongoing overdose-prevention training and naloxone access. If Vivitrol fits your recovery goals, Healing Sky can connect you with a provider to start that conversation, weigh the options, and prepare safely.
Medically reviewed by Cynthia Abraham, D.O.
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