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Naltrexone Implant

By Naltrexone Reviews Editorial TeamUpdated 28 sourcesHow we check

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Short answer

A naltrexone implant is a set of pellets placed under the skin that release naltrexone for weeks to months. No implant is FDA-approved in the US. Trials in Russia, Australia and Norway found less opioid use or relapse than with daily pills or usual care. The long-acting form the FDA has approved is Vivitrol, a shot given once a month.1-5

Key takeaways

  • Aetna's coverage policy calls naltrexone implants "experimental, investigational, or unproven" for alcohol and opioid addiction. The policy does not apply to Vivitrol.6
  • A 2014 review of 5 implant trials (576 people) rated the evidence moderate to very low and said implant use "should be limited to clinical trials."7
  • Overdose deaths have happened with an implant in place. Of 74 Australians who died while on naltrexone for opioid dependence from 2000 to 2017, most died of opioid overdose, and 32% had a recent implant.8,9

No naltrexone implant is FDA-approved

FDA's drug approval records list naltrexone tablets, the Vivitrol shot and combination products. None of the listings is an implant.1

No naltrexone implant is FDA-approved

  • Where: United States

    Status
    Approved forms: 50 mg tablets and the monthly Vivitrol shot1
    Source date
    Records updated October 16, 2026

  • Where: US insurer (Aetna)

    Status
    Experimental for alcohol and opioid addiction; no billing code for implants6
    Source date
    Policy last reviewed December 22, 2025

  • Where: Australia

    Status
    Described as an unlicensed product used to treat heroin dependence10
    Source date
    2008 study

  • Where: Russia

    Status
    An implant that blocks opioids for 60 to 90 days was registered there2
    Source date
    2012 trial report

In the US, an implant can be studied in a registered trial (see the trials below) or made by a compounder. Compounded drugs are not FDA-approved: FDA does not check their safety, effectiveness or quality before they are sold.11

Why a naltrexone implant is listed on DailyMed

DailyMed, run by the National Library of Medicine, posts the labeling that companies submit to FDA. That includes unapproved prescription products, and the library does not review the content before it goes up. Drugs that DailyMed marks "unapproved" have not been approved or evaluated by FDA.12

The naltrexone implant page on DailyMed is one of these13:

  • Who listed it. Complete Pharmacy and Medical Solutions, registered as a human drug compounding outsourcing facility. The label was last updated March 19, 2018.
  • Status. The marketing category is "unapproved drug other," and the page carries this notice: "This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA."
  • Product code. DailyMed marks the kit's only product code as inactivated, under a listing flag tied to an FDA-initiated compliance action.
  • What is in the kit. Six 200 mg pellets placed under the skin through a 4.5 mm tube. Each pellet also contains 3% triamcinolone, a steroid, as a second active ingredient. (The implant in the 2012 Russian trial also had a small steroid dose, added to prevent inflammation.2)
  • The evidence it cites. A 12-week placebo-controlled trial in Mexico in which 25 people received the implant, with no journal reference. Its liver-test section reports results from trials of the naltrexone injection, such as "89% had a baseline diagnosis of hepatitis C infection."

Implant, monthly shot or daily tablet

Implant, monthly shot or daily tablet

  • FDA-approved

    Implant
    No1
    Vivitrol shot
    Yes1
    Tablet
    Yes1

  • How it's given

    Implant
    Pellets put under the skin in a minor surgical procedure14
    Vivitrol shot
    380 mg injected into a buttock muscle by a provider5
    Tablet
    50 mg by mouth1

  • How long it blocks opioids

    Implant
    Weeks to months, depending on the product (next section)
    Vivitrol shot
    About 28 days5
    Tablet
    About a day (details)

  • Can it be taken out?

    Implant
    Some can be removed surgically; others dissolve and are not removed2,15,16
    Vivitrol shot
    No. The label explains it is "not an implanted device"5
    Tablet
    Stop taking it

  • Insurance

    Implant
    Aetna: experimental6
    Vivitrol shot
    Covered by many plans (Vivitrol cost)
    Tablet
    Covered by many plans

Pill and shot are compared head to head on naltrexone vs Vivitrol.

How long an implant lasts depends on the product

There is no standard implant. Each product releases naltrexone at its own rate, and studies measure it against different blood levels.

How long an implant lasts depends on the product

  • Product (study): 2.3 g implant (Hulse 2009, Perth)3

    People
    70 randomized; implant group measured
    Naltrexone level held for
    Above 2 ng/mL: 56 days in men, 43 days in women. Above 1 ng/mL: 101 days in men, 124 in women

  • Product (study): 1.1 g, 2.2 g and 3.3 g implants (Ngo 2008, Perth)17

    People
    10, 24 and 50
    Naltrexone level held for
    Above 2 ng/mL: 95, 136 and 145 days

  • Product (study): 6-month implant (Kunøe 2009, Norway)4

    People
    56 randomized
    Naltrexone level held for
    Above 1 ng/mL for 6 months

  • Product (study): DailyMed compounded kit, 1,200 mg13

    People
    No data given
    Naltrexone level held for
    Label says release over 10 to 12 weeks

The "6-month implant" holds only for some products, and only at the lower 1 ng/mL cutoff. The Vivitrol shot is given every 4 weeks or once a month.5

Trials abroad found less opioid use than with pills or usual care

Every completed efficacy trial below was run outside the US, and most compared the implant with daily tablets or no medicine, not with buprenorphine or methadone.

Trials abroad found less opioid use than with pills or usual care

  • Trial: Krupitsky 2012, St Petersburg, Russia, 24 weeks2

    People
    306 after opioid detox
    Compared with
    Oral naltrexone; placebo
    Result at the end
    Still in treatment without relapse: 54 of 102 (52.9%) on the implant, 16 of 102 (15.7%) on tablets, 11 of 102 (10.8%) on placebo

  • Trial: Hulse 2009, Perth, Australia, 6 months3

    People
    70 with heroin dependence
    Compared with
    Oral naltrexone
    Result at the end
    Fewer returned to regular heroin use; median time to return 158 vs 115 days

  • Trial: Kunøe 2009, Norway, 180 days4

    People
    56 after inpatient treatment
    Compared with
    Usual aftercare (open-label)
    Result at the end
    45 fewer days of heroin use on average

  • Trial: Krupitsky 2019, St Petersburg, 48 weeks18

    People
    200 with HIV and opioid addiction
    Compared with
    Oral naltrexone
    Result at the end
    HIV viral load suppressed in 66 of 100 vs 50 of 100 at 48 weeks; no difference at 24 weeks

Two reviews put these results in context:

  • Larney 2014 (5 trials, 576 people): implants cut opioid use compared with placebo implants and with tablets (risk ratio 0.57 for each, 2 trials apiece). One low-quality trial found no difference from methadone.7
  • Cochrane 2025 (22 trials, 3,416 people) pooled monthly shots and implants, so most of its results are not implant-specific. Against buprenorphine or methadone (3 trials), it found probably slightly more illicit opioid use during treatment with long-acting naltrexone (risk ratio 1.15, moderate certainty), a result from a single 570-person trial.19 How naltrexone compares with Suboxone is on naltrexone vs Suboxone.

For alcohol, the evidence is thinner. In a 70-person trial at one hospital in China, people given an implant (47) had a median of 1.49% heavy-drinking days over 24 weeks, against 13.39% on a placebo implant (23). The result was reported in a 2026 paper on blood lipids, which credits the implant maker's clinical program.20 The 70 people appear to be part of that maker's 210-person, three-arm phase 2 trial (same doses, province and dates), which is listed as completed in October 2024 with no results posted. Its phase 3 trial is listed as not yet recruiting.21,22

Wound infections, removal surgery and overdose

  • Wound infections. In the 2012 Russian trial, 12 of 244 implant procedures (4.9%) led to a wound infection, against 2 of 181 (1.1%) and 1 of 148 (0.7%) in the placebo-implant groups. All came in the first 2 weeks and cleared with antibiotics.2 The Perth trial had one serious wound bleed (hematoma).3
  • Hospital visits. Over 12 months in 2006 and 2007, two Sydney hospitals saw 8 admissions definitely or probably related to implants or the rapid detox done with them. Six were severe opioid withdrawal with dehydration; one was an infected implant site.10
  • Removal. At one Perth hospital, 37 people had implants taken out between 2001 and 2008, for infection, intolerance or the need for opioid pain relief. Of the 32 who had general anesthesia, 44% reported moderate to severe pain afterward.15
  • Overdose with an implant in place. Australian coroners' records from 2000 to 2004 include 5 deaths involving implants. In one, a man died of opioid overdose with an implant in place and a blood naltrexone level above reported blockade levels.8 A later review of 74 deaths among Australians on naltrexone for opioid dependence (2000 to 2017) attributed 86.5% to opioid toxicity; 32% of the people had a recent implant, and 14 died of opioid toxicity with naltrexone still detectable in blood or urine.9

Overdose warning

After any form of naltrexone wears off or stops, tolerance to opioids is lower, and a smaller dose than you used before can be fatal. Keep naloxone on hand and call 911 for any suspected overdose. See when the block fades.5

Naloxone (Narcan) is the drug that reverses an opioid overdose; naltrexone does not.23 See naltrexone vs naloxone.

Implants in US trials, as of October 17, 2026

ClinicalTrials.gov lists these US implant studies. Only the O'Neil phase 2 study is planned for people with opioid use disorder; the others enroll healthy volunteers to measure blood levels and safety.

Implants in US trials, as of October 17, 2026

  • Implant (sponsor): O'Neil Long Acting Naltrexone Implant, OLANI (Go Medical; collaborators include NIDA, New York State Psychiatric Institute and Columbia University)

    Study
    Phase 2, repeat dosing in people with opioid use disorder, 250 planned
    Registry status, October 17, 2026
    Not yet recruiting; estimated start January 1, 202724

  • Implant (sponsor): OLANI

    Study
    Phase 1, 20 healthy volunteers at Columbia
    Registry status, October 17, 2026
    Completed March 202125

  • Implant (sponsor): BICX104 pellets (BioCorRx Pharmaceuticals; NIDA)

    Study
    Phase 1, with or without bupropion, vs Vivitrol, 30 planned, Miami
    Registry status, October 17, 2026
    Recruiting; estimated completion December 5, 202614

  • Implant (sponsor): BICX104 (BioCorRx)

    Study
    Phase 1, 24 healthy volunteers, vs Vivitrol
    Registry status, October 17, 2026
    Completed March 202326

  • Implant (sponsor): BIOPIN 6 (Akyso Therapeutics; NIDA)

    Study
    Phase 1, 16 healthy adults
    Registry status, October 17, 2026
    Completed April 202527

  • Implant (sponsor): iSTEP-N (Akyso Therapeutics; NIDA)

    Study
    Phase 1b, two doses vs Vivitrol, 33 planned
    Registry status, October 17, 2026
    Active, not recruiting; estimated completion December 31, 202916

None of these listings reports results.

Cost and insurance

There is no US list price for an implant, and we found no dated US price we could cite. Aetna treats implants as experimental and lists no billing code for them.6 The approved long-acting option, Vivitrol, has cash, Medicare and Medicaid prices on naltrexone cost.

Had a naltrexone implant, here or abroad? Share what it was like.

Frequently asked questions

Is the naltrexone implant FDA approved?

No. FDA has approved naltrexone tablets and the monthly Vivitrol shot. See FDA status.1

How long does a naltrexone implant last?

It depends on the product: from about 6 weeks to 6 months, depending on the implant and the blood level measured. See the levels table.3,4,17

Can you get a naltrexone implant in the US?

Not as an approved product. Implants are being tested in registered US trials; see the table. See US trials.24

Does the naltrexone implant work for alcohol?

One 70-person trial in China reported fewer heavy-drinking days than placebo; the full 210-person trial it appears to belong to has posted no results. See the trials.20,21

How much does a naltrexone implant cost?

Implants have no US list price, and Aetna does not cover them. See cost and insurance.6

How we checked

FDA status: openFDA Drugs@FDA records and FDA's compounding Q&A. The DailyMed listing was read live and from its XML on October 17, 2026. Trials, reviews and the 2019 Australian death review: PubMed abstracts, plus the full text of Krupitsky 2012 and Huang 2026. US trial status: ClinicalTrials.gov records, read October 17, 2026. Status and evidence will be re-checked before publishing.1,11,13

Related guides

References

28 sources, numbered in the order they are first cited (AMA style). Each is labelled by type so you can weigh it; commercial and media sources are never the only support for a clinical claim.

  1. 1.Drugs@FDA: FDA-approved drugs. US Food and Drug Administration. Data updated October 16, 2026. Accessed October 17, 2026. https://www.accessdata.fda.gov/scripts/cder/daf/Government source
  2. 2.Krupitsky E, Zvartau E, Blokhina E, et al. Randomized trial of long-acting sustained-release naltrexone implant vs oral naltrexone or placebo for preventing relapse to opioid dependence. Arch Gen Psychiatry. 2012;69(9):973-981. doi:10.1001/archgenpsychiatry.2012.1aRandomized controlled trial · Our summary of this study
  3. 3.Hulse GK, Morris N, Arnold-Reed D, Tait RJ. Improving clinical outcomes in treating heroin dependence: randomized, controlled trial of oral or implant naltrexone. Arch Gen Psychiatry. 2009;66(10):1108-1115. doi:10.1001/archgenpsychiatry.2009.130Randomized controlled trial · Our summary of this study
  4. 4.Kunøe N, Lobmaier P, Vederhus JK, et al. Naltrexone implants after in-patient treatment for opioid dependence: randomised controlled trial. Br J Psychiatry. 2009;194(6):541-546. doi:10.1192/bjp.bp.108.055319Randomized controlled trial · Our summary of this study
  5. 5.Vivitrol (naltrexone for extended-release injectable suspension). Prescribing information and Medication Guide. Alkermes, Inc.; revised May 2026. DailyMed SPL version 39. Accessed October 17, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=cd11c435-b0f0-4bb9-ae78-60f101f3703fFDA drug label
  6. 6.Naltrexone implants. Clinical Policy Bulletin 0878. Aetna; last reviewed December 22, 2025. Accessed October 17, 2026. https://www.aetna.com/cpb/medical/data/800_899/0878.htmlCommercial source
  7. 7.Larney S, Gowing L, Mattick RP, Farrell M, Hall W, Degenhardt L. A systematic review and meta-analysis of naltrexone implants for the treatment of opioid dependence. Drug Alcohol Rev. 2014;33(2):115-128. doi:10.1111/dar.12095Systematic review / meta-analysis · Our summary of this study
  8. 8.Gibson AE, Degenhardt LJ, Hall WD. Opioid overdose deaths can occur in patients with naltrexone implants. Med J Aust. 2007;186(3):152-153. doi:10.5694/j.1326-5377.2007.tb01126.xResearch study · Our summary of this study
  9. 9.Darke S, Farrell M, Duflou J, Larance B, Lappin J. Circumstances of death of opioid users being treated with naltrexone. Addiction. 2019;114(11):2000-2007. doi:10.1111/add.14729Research study · Our summary of this study
  10. 10.Lintzeris N, Lee S, Scopelliti L, Mabbutt J, Haber PS. Unplanned admissions to two Sydney public hospitals after naltrexone implants. Med J Aust. 2008;188(8):441-444. doi:10.5694/j.1326-5377.2008.tb01712.xResearch study · Our summary of this study
  11. 11.Compounding and the FDA: questions and answers. US Food and Drug Administration. Content current as of September 16, 2025. Accessed October 17, 2026. https://www.fda.gov/drugs/human-drug-compounding/compounding-and-fda-questions-and-answersGovernment source
  12. 12.About DailyMed. National Library of Medicine. Accessed October 17, 2026. https://dailymed.nlm.nih.gov/dailymed/about-dailymed.cfmGovernment source
  13. 13.Naltrexone implant. Label. Complete Pharmacy and Medical Solutions; updated March 19, 2018. DailyMed setid 40b16844-bc1c-485e-aad3-2cb86e2eb009. Accessed October 17, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=40b16844-bc1c-485e-aad3-2cb86e2eb009Commercial source
  14. 14.Safety and PK study of BICX104 with or without bupropion compared to Vivitrol. ClinicalTrials.gov identifier: NCT07269873. Updated May 13, 2026. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT07269873Government source
  15. 15.Sadleir PH, Gardner AI, Hennessy B. Adverse events in the removal of naltrexone implants. Anaesth Intensive Care. 2011;39(5):895-898. doi:10.1177/0310057X1103900515Research study · Our summary of this study
  16. 16.iSTEP-N 101b: pharmacokinetics and safety study of low- and high-dose naltrexone implants vs monthly Vivitrol in healthy volunteers. ClinicalTrials.gov identifier: NCT07064564. Updated September 30, 2026. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT07064564Government source
  17. 17.Ngo HT, Arnold-Reed DE, Hansson RC, Tait RJ, Hulse GK. Blood naltrexone levels over time following naltrexone implant. Prog Neuropsychopharmacol Biol Psychiatry. 2008;32(1):23-28. doi:10.1016/j.pnpbp.2007.06.007Research study · Our summary of this study
  18. 18.Krupitsky E, Blokhina E, Zvartau E, et al. Slow-release naltrexone implant versus oral naltrexone for improving treatment outcomes in people with HIV who are addicted to opioids: a double-blind, placebo-controlled, randomised trial. Lancet HIV. 2019;6(4):e221-e229. doi:10.1016/S2352-3018(18)30362-XRandomized controlled trial · Our summary of this study
  19. 19.Kornør H, Lobmaier PPK, Kunøe N. Sustained-release naltrexone for opioid dependence. Cochrane Database Syst Rev. 2025;5(5):CD006140. doi:10.1002/14651858.CD006140.pub3Systematic review / meta-analysis · Our summary of this study
  20. 20.Huang L, Zhou B, Ou Q, Yin J, Tian X, Zhou X. A membrane-centric plasma lipidomic signature of response to long-acting naltrexone in alcohol use disorder. Addict Biol. 2026;31(5):e70165. doi:10.1111/adb.70165Research study · Our summary of this study
  21. 21.Phase II clinical study on the efficacy and safety of naltrexone implant in patients with alcohol use disorder. ClinicalTrials.gov identifier: NCT07333638. Updated January 12, 2026. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT07333638Government source
  22. 22.Evaluate the efficacy and safety of naltrexone hydrochloride implant in patients with alcohol use disorder. ClinicalTrials.gov identifier: NCT07433413. Updated February 25, 2026. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT07433413Government source
  23. 23.Narcan (naloxone hydrochloride) nasal spray 4 mg. Drug Facts label (over-the-counter). Emergent Devices Inc.; DailyMed SPL version 4 (August 17, 2026). Accessed October 17, 2026. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a0ebc83d-2892-40de-bc0a-775ce90b30dbFDA drug label
  24. 24.Evaluation of the O'Neil Long Acting Naltrexone Implant in opioid dependent persons. ClinicalTrials.gov identifier: NCT05382091. Updated September 28, 2026. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT05382091Government source
  25. 25.The O'Neil Long Acting Naltrexone Implant (OLANI) pharmacokinetic (PK)/safety study in healthy volunteers. ClinicalTrials.gov identifier: NCT03810495. Updated November 12, 2024. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT03810495Government source
  26. 26.Pharmacokinetic and safety study of naltrexone release from subcutaneous BICX104 pellets compared to Vivitrol injections. ClinicalTrials.gov identifier: NCT04828694. Updated August 16, 2023. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT04828694Government source
  27. 27.Study of the BIOPIN 6 naltrexone implant in healthy adults. ClinicalTrials.gov identifier: NCT06216132. Updated April 28, 2026. Accessed October 17, 2026. https://clinicaltrials.gov/study/NCT06216132Government source
  28. 28.SAMHSA's National Helpline. Substance Abuse and Mental Health Services Administration. Updated June 9, 2023. Accessed October 17, 2026. https://www.samhsa.gov/find-help/helplines/national-helplineGovernment source

Medical disclaimer

This page is for general information only and is not medical advice. It does not replace advice from your own clinician or pharmacist. Don't start, stop or change a medicine without talking to your prescriber. If you use opioids, starting naltrexone in any form can cause sudden, severe withdrawal. For free, confidential treatment referrals 24 hours a day, call SAMHSA's National Helpline at 1-800-662-4357.28

Full medical disclaimer.