Dr George O’Neil: Developer of the O’Neil Long-Acting Naltrexone Implant
DeBinge opioid transition: When travelling to DeBinge in The Bahamas for OLANI treatment, there is no requirement to complete a separate opioid-free waiting window before arrival. DeBinge uses a medically supervised 4-to-5-day buprenorphine transition. Buprenorphine is introduced to bridge the patient away from full-agonist opioids, stabilised and tapered over the first several days, and the O’Neil Long-Acting Naltrexone Implant is typically inserted around day 4 or 5 while buprenorphine is still being tapered. The planned overlap continues as buprenorphine clears and the implant gradually releases naltrexone. This pathway is clinician-supervised because mistimed naltrexone exposure can precipitate withdrawal.
Based on DeBinge’s clinical experience in The Bahamas since 2018, the implant typically provides its strongest craving and relapse-prevention support on average 9 months, while clinically meaningful opioid-receptor blockade may persist for longer, in some patients up to about 15 months. This longer blockade may continue to reduce opioid effects and overdose risk.
Ongoing recovery: The implant is not a cure. The DeBinge programme includes a full year of professional counselling after implantation to address the behavioural and psychological side of addiction.
The story of an Australian physician, medical inventor and addiction-medicine specialist whose work helped move sustained-release naltrexone from an experimental drug-delivery concept into decades of clinical development, research and international investigation.
Who is Dr George O’Neil?
Dr George O’Neil is an Australian physician, medical inventor and addiction-medicine specialist closely associated with the development of the Australian O’Neil Long-Acting Naltrexone Implant, commonly known as OLANI.
His career has included obstetrics and gynaecology, medical-device development, drug-delivery technology, addiction medicine, rehabilitation services and research into long-duration pharmaceutical delivery.
Fresh Start has described Dr O’Neil as an Addiction Medicine Specialist and lists professional qualifications including MBBS, FRCOG, FRACOG, DDU and FChAM. His work has extended beyond addiction medicine into products and research involving obstetrics, urinary catheterisation, pain management, intravenous therapy and controlled drug delivery.
It is important to describe his contribution accurately. Dr O’Neil did not invent the molecule naltrexone itself, and implant or depot concepts involving naltrexone existed before his work. His major contribution was developing and clinically advancing a particular biodegradable, sustained-release naltrexone implant system through Go Medical Industries and the addiction-treatment programme built around it in Western Australia.
A medical inventor before the OLANI programme
Dr O’Neil’s interest in medical innovation began well before sustained-release naltrexone. Go Medical Industries was established in Perth in the 1980s following his clinical work in obstetrics and gynaecology in Australia and overseas.
O’Neil urinary catheter technology
One of Go Medical’s early areas of development involved urinary catheterisation. The O’Neil catheter concept incorporated an introducer designed to reduce contact between the catheter and heavily colonised tissue around the urethral opening.
Obstetric medical devices
Dr O’Neil and Go Medical were involved in obstetric-device development including products associated with amniotomy and vacuum-assisted delivery.
Historical U.S. regulatory records also document Go Medical obstetric products entering the American medical-device regulatory system.
Infusion and controlled drug delivery
Go Medical later worked with intravenous delivery products, flow-control systems, patient-controlled analgesia and other forms of controlled drug administration.
This experience in sustained and controlled drug delivery later became relevant to the development of long-acting pharmaceutical formulations.
Businesses and programmes founded or led by Dr O’Neil
Go Medical Industries Pty Ltd
Go Medical Industries is an Australian medical-technology company established by Dr George O’Neil in Perth.
Its documented areas of work have included:
- urinary catheterisation;
- obstetric medical devices;
- infusion systems;
- intravenous drug delivery;
- flow-control technology;
- patient-controlled analgesia;
- controlled-release pharmaceutical development;
- the O’Neil Long-Acting Naltrexone Implant.
The company’s work increasingly moved into pharmaceutical drug delivery as Dr O’Neil became more involved in addiction treatment.
Fresh Start Recovery Programme
Fresh Start was founded in Western Australia in the 1990s and developed into a broader addiction-treatment and rehabilitation organisation.
The programme’s work has included medical treatment, counselling, rehabilitation, social support, family involvement and assistance with rebuilding life after addiction.
This is an important part of Dr O’Neil’s treatment philosophy: pharmacological blockade can potentially create a period of stability, but medication alone cannot automatically resolve the psychological, social and behavioural factors associated with addiction.
Western Australian parliamentary discussion in 2025 described Fresh Start as having seen and treated approximately 15,300 patients over 24 years. This is a reported service-volume figure and should not be interpreted as a success rate.
From oral naltrexone to long-acting implantation
The OLANI programme developed gradually through formulation work, clinical experience, academic collaboration, publications and later U.S. regulatory development.
Fresh Start develops
Fresh Start emerged as a Western Australian addiction-treatment and rehabilitation programme that would later become closely associated with Dr O’Neil’s naltrexone work.
Oral naltrexone treatment programme
Dr O’Neil became involved in oral naltrexone treatment for opioid dependence in Perth. Western Australian authorities also became involved in monitoring and evaluating naltrexone treatment.
OLANI development begins
Go Medical’s development history records formal research into a biodegradable sustained-release naltrexone implant, including laboratory work examining formulation and release characteristics.
Early clinical use
Following laboratory and preclinical work, implant use began in selected Australian patients through pathways available for unapproved therapeutic products.
This was not equivalent to routine product registration or U.S. FDA approval.
Early peer-reviewed research
Australian researchers including Gary Hulse and George O’Neil published work examining sustained-release naltrexone, blood concentrations, repeated implantation and specialised clinical situations.
Hepatitis C treatment research
A published Australian programme examined hepatitis C treatment among people with histories of injecting drug use receiving addiction care that included naltrexone-implant treatment.
Randomised implant-versus-oral naltrexone trial
A randomised controlled study involving 70 heroin-dependent participants in Perth compared an O’Neil sustained-release naltrexone implant with daily oral naltrexone over six months.
Alcohol and flumazenil-related research
Researchers associated with Fresh Start and Dr O’Neil published work examining health-service use following implant naltrexone treatment for problematic alcohol use.
Dr O’Neil also became involved in research exploring controlled and sustained delivery of flumazenil.
U.S. investigational development pathway
Go Medical reported that a U.S. Investigational New Drug pathway for its subcutaneous naltrexone implant became effective, allowing formal clinical investigation to proceed.
Investigational status allows research. It does not mean the product is FDA-approved.
U.S. Phase 1 research
A 20-participant open-label pharmacokinetic and safety study investigated OLANI with collaborators including U.S. academic and research institutions.
Clinical-trial results reported
Results associated with the U.S. OLANI study were posted and updated through the ClinicalTrials.gov system. The study is recorded as completed.
Continuing research and development
U.S. federal research records indicate continuing work related to OLANI safety, pharmacokinetics and product development.
Continuing clinical development should not be confused with regulatory approval.
Dr George O’Neil’s opioid-to-naltrexone transition method
Alongside development of the O’Neil Long-Acting Naltrexone Implant, Dr George O’Neil and the Perth treatment programme developed and used a structured, medically supervised opioid-detoxification and naltrexone-induction approach for transitioning opioid-dependent patients toward antagonist treatment.
DeBinge describes the current Bahamas adaptation of this approach as a clinician-led transition that uses buprenorphine to bridge patients away from full-agonist opioids before and during introduction of long-acting naltrexone. The aim is to reduce the severity of withdrawal and avoid requiring patients to complete a prolonged unsupported “cold-turkey” detox before implantation.
The transition framework used by the programme
Day 1 — move away from full-agonist opioids.
Buprenorphine is introduced under medical supervision to suppress acute withdrawal and provide a controlled bridge away from opioids such as heroin, fentanyl or other full agonists.
Days 2–3 — stabilisation and tapering.
Buprenorphine is maintained and then reduced according to the patient’s clinical response. The objective is to keep withdrawal manageable while progressively lowering opioid-receptor stimulation.
Around day 4 or 5 — long-acting naltrexone implantation.
Once the treating team judges that the transition has progressed sufficiently, the O’Neil Long-Acting Naltrexone Implant is inserted under local anaesthesia as a minor surgical procedure.
Overlap rather than a hard stop.
A distinctive feature of the O’Neil method is the planned overlap between the final phase of buprenorphine treatment and the gradual release of naltrexone from the implant. Buprenorphine has very high affinity for the mu-opioid receptor. As it is tapered and clears, naltrexone exposure from the implant increases and progressively occupies receptors as they become available.
In practical terms, the programme is designed as a controlled pharmacological handover rather than a sudden switch from opioid agonism to full antagonist blockade. The intended clinical benefit is a more manageable transition with less severe withdrawal than an abrupt, unsupported stop.
Dr O’Neil’s published work includes rapid opioid detoxification and protocols for moving opioid-dependent patients toward sustained-release naltrexone treatment. This work formed part of the wider clinical programme around antagonist blockade and long-acting implantation.
Historical contribution: Dr O’Neil can reasonably be described as a developer and pioneer of a specific opioid-to-naltrexone transition protocol used within his Perth programme and adapted within the Bahamas treatment pathway. This should not be confused with inventing naltrexone, naloxone, buprenorphine or opioid detoxification itself.
Sources include O’Neil and colleagues’ Rapid opioid detoxification in Australia, published literature on buprenorphine-to-naltrexone induction, and DeBinge’s description of the clinician-supervised Bahamas protocol.
What problem was the O’Neil implant designed to address?
Oral naltrexone can block opioid receptors, but its effectiveness depends partly on whether a person continues taking the medication. Dr O’Neil’s development work focused on a different question: could antagonist exposure be maintained for months without daily dosing?
The O’Neil implant was developed using naltrexone incorporated into biodegradable material intended to release medication gradually after subcutaneous implantation.
Different generations and doses of the implant have been investigated over time. Therefore, the duration reported for one historical formulation should not automatically be applied to every OLANI formulation.
The adherence rationale is straightforward: sustained delivery reduces dependence on remembering, choosing or being able to take a daily tablet.
That does not mean an implant independently produces recovery. Addiction treatment may also require counselling, behavioural treatment, psychiatric care, family involvement, stable housing, social support and continuing medical follow-up.
What has research involving the O’Neil implant found?
The O’Neil programme has contributed to case reports, pharmacokinetic studies, observational research, controlled research and later U.S. clinical development.
These forms of evidence have different strengths and limitations and should not be treated as if they all provide the same level of certainty.
2009 randomised controlled trial
One of the most frequently discussed studies randomised 70 heroin-dependent volunteers in Perth to sustained-release implant naltrexone or oral naltrexone.
A University of Western Australia summary reported that 17% of participants assigned to the implant group returned to regular heroin use compared with 62% in the oral-naltrexone group. It also reported complete abstinence in 63% of implant participants compared with 26% of participants assigned to oral naltrexone.
Alcohol-related research
Dr O’Neil was also involved in research examining patients receiving implant naltrexone for problematic alcohol use.
One observational study compared hospital, emergency and outpatient health-care use before and after treatment. Lower health-system utilisation and costs were reported during the post-treatment period.
Because this was observational rather than a randomised comparison, it cannot establish that the implant alone caused the observed changes.
Research involving pregnancy
Early publications also described small groups of pregnant women with opioid dependence who were managed using naltrexone implants.
These were specialised and relatively small studies and should not be interpreted as establishing routine treatment recommendations for pregnancy.
Hepatitis C shared-care research
Dr O’Neil participated in research integrating hepatitis C treatment with addiction care among people with histories of injecting drug use.
This work was significant because it challenged the idea that people with substance-use histories should automatically be excluded from antiviral hepatitis C treatment.
How many patients has Dr George O’Neil’s programme treated?
Dr O’Neil’s work progressed far beyond small clinical studies. Western Australian parliamentary discussion in 2025 described Fresh Start Recovery Programme, founded by Dr O’Neil, as having seen and treated approximately 15,300 patients over 24 years. Earlier conference material from O’Neil described approximately 12,000 patients treated with the antagonist-based approach in Perth. These figures describe the scale of the programme and should not be interpreted as treatment-success rates or as meaning that Dr O’Neil personally performed every treatment.
From development programme to large-scale treatment experience
Fresh Start accumulated a larger real-world treatment experience than the number of participants enrolled in individual clinical trials.
A scientific meeting report examining the early years of the Perth programme described more than 1,500 patients receiving implant treatment between 2000 and 2005.
Later reports describe substantially larger numbers of patients receiving care through Dr O’Neil’s broader treatment programme.
Nevertheless, the scale of the programme is historically important because it produced a relatively large amount of practical clinical experience with sustained-release naltrexone and helped generate questions that later moved into academic and regulatory research.
OLANI, U.S. researchers and the FDA investigational pathway
A later stage of Dr O’Neil’s work involved attempting to move OLANI through the formal U.S. clinical-development system.
An Investigational New Drug pathway allowed OLANI to be evaluated in a controlled U.S. research setting.
ClinicalTrials.gov
ClinicalTrials.gov records a Phase 1 pharmacokinetic and safety study involving 20 healthy volunteers.
The study is listed as completed.
NIDA collaboration
The National Institute on Drug Abuse has been associated with research supporting evaluation of the OLANI formulation.
Academic collaboration
U.S. development has involved researchers and institutions experienced in addiction pharmacotherapy and clinical drug development.
Other medical and research projects involving Dr O’Neil
Flumazenil and benzodiazepine research
Dr O’Neil participated in research examining controlled subcutaneous delivery of flumazenil in people with long-term benzodiazepine use.
Work in this area included investigation of infusion and sustained-release approaches.
Idiopathic hypersomnia research
Dr O’Neil was involved in a case report examining subcutaneous and sustained-release flumazenil in an individual with idiopathic hypersomnia.
A case report can generate research questions but cannot establish general treatment efficacy.
Hepatitis C treatment access
His collaborative work included treatment programmes linking addiction care with hepatitis C medical treatment.
Medical-device development
His wider career has included technology associated with obstetrics, catheterisation, intravenous infusion, controlled drug delivery and pain management.
Organisations connected with his clinical or research work
Dr O’Neil’s work has involved collaborations spanning clinical care, medical technology, universities and addiction research.
| Organisation | Documented connection |
|---|---|
| Fresh Start Recovery Programme | Addiction-treatment and rehabilitation organisation founded by Dr O’Neil in Western Australia. |
| Go Medical Industries Pty Ltd | Medical-device and pharmaceutical-development company founded by Dr O’Neil. |
| University of Western Australia | Researchers affiliated with UWA participated in multiple studies involving sustained-release naltrexone. |
| Curtin University | Research collaboration in areas including pharmaceutical formulation and drug-delivery science. |
| Western Australian health services | Clinical and research work involving addiction treatment and related medical care. |
| Columbia University / New York State Psychiatric Institute | Associated with the U.S. research programme evaluating OLANI. |
| National Institute on Drug Abuse | Associated with U.S. research and federal support for OLANI development. |
| Clinilabs | Listed among collaborators associated with U.S. OLANI clinical research. |
Government support, scientific interest and regulatory debate
Dr O’Neil’s naltrexone work received substantial attention in Western Australia. Government agencies became involved in funding, evaluation and debate around the appropriate role of sustained-release naltrexone.
The programme attracted both supporters and critics.
Supporters highlighted the potential adherence advantage of long-acting antagonist treatment and reported clinical outcomes.
Regulators and researchers emphasised the importance of independent evidence, manufacturing standards, safety surveillance and formal product registration.
How does Dr O’Neil’s work fit into today’s evidence?
Contemporary research into sustained-release naltrexone extends well beyond one product, researcher or country.
The evidence base now includes implantable and injectable formulations, randomised trials, systematic reviews and comparisons with other forms of treatment for opioid use disorder.
Research suggests sustained-release formulations can address some of the adherence limitations associated with daily oral naltrexone. However, important questions remain about formulation-specific effectiveness, long-term safety, retention in treatment and how antagonist treatment compares with other medications across different patient populations.
Why Dr George O’Neil’s work remains significant
Dr O’Neil’s career connects several areas that are often treated separately: clinical medicine, medical-device engineering, pharmaceutical delivery, addiction medicine, rehabilitation services and translational research.
His earlier medical inventions addressed practical clinical problems. The same approach later appeared in addiction medicine.
Oral naltrexone could provide opioid-receptor blockade, but adherence remained difficult. Dr O’Neil therefore pursued a formulation designed to continue releasing medication without requiring daily dosing.
The result grew into more than a pharmaceutical formulation. It became a programme involving medical-device expertise, manufacturing, addiction treatment, rehabilitation services, academic collaboration, peer-reviewed research and later U.S. clinical development.
Whether OLANI ultimately achieves regulatory approval in additional jurisdictions remains a separate scientific and regulatory question.
Dr O’Neil’s established historical contribution is helping develop and investigate one of Australia’s best-known long-duration naltrexone implant programmes and keeping sustained-release antagonist treatment under clinical and scientific investigation for more than two decades.
Learn more about long-acting naltrexone
Long-Acting Naltrexone Implant
Understand naltrexone’s mechanism, implant delivery, preparation, evidence, safety and regulatory status.
Oral Naltrexone vs Vivitrol vs Implant
Compare daily oral naltrexone, extended-release injectable naltrexone and longer-acting implant formulations.
Where is implant treatment available?
Understand the difference between U.S. FDA-approved naltrexone options and implant-based treatment in The Bahamas.
Considering long-acting naltrexone treatment?
Substance use history, current medication, opioid exposure, withdrawal risk, medical history and treatment goals all matter. Decisions about naltrexone should begin with individual clinical assessment rather than relying on a single article or research study.
Questions about Dr George O’Neil and OLANI
Did Dr George O’Neil invent naltrexone?
No. Naltrexone existed before Dr O’Neil’s work. His major contribution was the development and clinical evolution of a particular long-acting biodegradable naltrexone implant formulation and treatment programme.
Was Dr O’Neil the first person to develop a naltrexone implant?
Earlier depot and implant concepts involving naltrexone existed. Dr O’Neil became a major developer of a later Australian sustained-release formulation intended to provide prolonged naltrexone exposure.
What does OLANI mean?
OLANI refers to the O’Neil Long-Acting Naltrexone Implant, a sustained-release naltrexone formulation developed through Go Medical Industries.
When did development of OLANI begin?
Go Medical’s development history places formal OLANI work in the late 1990s, followed by early preclinical research and clinical use in Australia around 2000.
Is the O’Neil naltrexone implant FDA approved?
No. OLANI has undergone investigational research in the United States, including a pharmacokinetic and safety study, but naltrexone implant formulations are not FDA-approved medications for routine clinical use in the United States.
Has OLANI been studied in the United States?
Yes. ClinicalTrials.gov records a completed U.S. pharmacokinetic and safety study involving 20 healthy volunteers and research collaborators experienced in addiction pharmacotherapy.
Did the O’Neil implant perform better than oral naltrexone in research?
A 2009 randomised Perth study reported better outcomes on several measures for the sustained-release implant group compared with the oral-naltrexone group. The study was relatively small and involved a specific historical implant formulation, so its results should be interpreted within the wider evidence base.
Is a naltrexone implant a complete addiction treatment?
No. Medication may be one component of treatment. Counselling, mental-health care, social stability, family support, relapse-prevention planning and continuing medical care may also be important.
Prepared for Medical Review by Dr Fergus Law, BSc, MBChB, FRCPsych
Consultant Psychiatrist specialising in substance misuse and addiction psychiatry.
Review status: Pending clinical approval.
View Dr Fergus Law’s professional profile →
This article should only be changed to “Medically reviewed” after Dr Fergus Law has personally reviewed and approved the final published version.
Sources informing this profile
This profile distinguishes historical records, peer-reviewed research, regulatory information, clinical-service reports and later development programmes. Findings from one study or implant formulation should not automatically be applied to every sustained-release naltrexone product.
- Fresh Start Recovery Programme. Professional information describing Dr George O’Neil’s medical background, addiction-medicine work and involvement in Fresh Start.
- Go Medical Industries. Company history describing medical-device development, controlled drug delivery and the development of the O’Neil Long-Acting Naltrexone Implant.
- Go Medical OLANI development history. Historical information covering laboratory development, preclinical work and early clinical use.
- U.S. Food and Drug Administration medical-device records. Historical regulatory records associated with earlier Go Medical medical devices.
- Hulse GK and colleagues. Randomised controlled research comparing sustained-release implant naltrexone with oral naltrexone in heroin-dependent participants.
- University of Western Australia. University reporting on implant-versus-oral naltrexone research conducted in Perth.
- Australian pharmacokinetic research. Studies examining naltrexone and metabolite concentrations following sustained-release implants.
- Hepatitis C treatment research. Collaborative work examining antiviral therapy among people receiving addiction treatment following injecting-drug use.
- Alcohol-related implant research. Observational research examining health-service utilisation before and after implant naltrexone treatment for problematic alcohol use.
- Flumazenil research. Published work involving controlled or sustained-release delivery in specialised clinical settings.
- ClinicalTrials.gov. U.S. clinical-trial registration and results for OLANI pharmacokinetic and safety research.
- U.S. academic addiction-research collaborators. Information relating to later clinical development of OLANI in the United States.
- National Institute on Drug Abuse and federal research records. Information associated with U.S. research support for sustained-release naltrexone development.
- Western Australian government and parliamentary records. Historical information concerning Fresh Start, government support, public-health discussion and reported service volume.
- Contemporary systematic reviews of sustained-release naltrexone. Evidence examining implantable and injectable formulations and the strengths and limitations of the current research base.
Last evidence update: September 2026. This page is educational and biographical and is not a substitute for individual medical advice, diagnosis or treatment. Medical evidence and regulatory status can change and should be confirmed before treatment decisions are made.