Public record
Naltrexone: the public record
Each table is computed from the named federal dataset as of its data date; the method is under each one.
Approvals
FDA approval history for naltrexone
The earliest FDA approval on file for a naltrexone product is 1984-11-20. Drugs@FDA lists 10 applications for it and 56 approved supplements, the most recent on 2025-12-22.
| Measure | Value | Note |
|---|---|---|
| Earliest FDA approval on file | 1984-11-20 | |
| Applications with an approval on file | 10 | |
| New drug applications (NDA) | 2 | |
| Generic applications (ANDA) | 8 | |
| Approved supplements | 56 | label, manufacturing and efficacy changes |
| Most recent supplement approval | 2025-12-22 | |
| Sponsoring companies | 10 |
How this was calculated
Selected applications with a product whose only active ingredient is this substance, then counted approved original and supplemental submissions. The earliest approved original submission is the first approval.
Applications with a single-ingredient naltrexone product in Drugs@FDA, all sponsors and strengths
Older approvals can be missing dates, and tentative approvals are not counted. An approved application does not mean the product is currently marketed.
Patents and generics
Patents and generic approvals for naltrexone
The FDA Orange Book lists 8 approved generic applications for naltrexone, the first approved on 1998-05-08. 1 listed patent on specific brand products has not yet expired, the last on 2029-10-15; generics of other versions are already approved.
| Measure | Value | Note |
|---|---|---|
| Brand-name applications (NDA) | 2 | |
| Approved generic applications (ANDA) | 8 | first approved 1998-05-08 |
| Companies with a generic not marked discontinued | 7 | |
| Listed patents not yet expired | 1 | |
| Latest listed patent expiry | 2029-10-15 | on any product; may cover only one brand formulation |
| Earliest approval date on file | 1984-11-20 | |
| Products not marked discontinued | 10 of 12 |
How this was calculated
Selected Orange Book products whose only active ingredient is this substance, then counted applications by type and the distinct patents and exclusivities listed against them. Expired patents are left out.
All single-ingredient naltrexone products in the Orange Book, every brand and strength, files dated 2026-10-09
An approved generic or an expired patent does not show that a generic is on sale. Launch timing also depends on litigation, settlements and supply. Biologics and compounded products are not in the Orange Book.
Adverse event reports
Most reported events in FDA adverse event reports for naltrexone
Through 2026-10-28, FDA had received 32,182 adverse event reports for naltrexone, 9,422 of them marked serious by the reporter. The symptom terms named most often were injection site reaction (4,389), injection site pain (3,172) and nausea (2,244).
| Measure | Value | Note |
|---|---|---|
| All reports received | 32,182 | |
| Reports the reporter marked serious | 9,422 | death, hospitalisation, disability or similar outcome |
| Injection site reaction | 4,389 reports | |
| Injection site pain | 3,172 reports | |
| Nausea | 2,244 reports | |
| Fatigue | 2,012 reports | |
| Alcoholism | 1,956 reports |
How this was calculated
Counted FAERS reports listing this active substance, then the reaction terms named most often. A report can name several reactions, and a term can describe the illness being treated and not an effect of the drug.
Reports where FDA recorded naltrexone as a single-ingredient active substance (any brand), all years to 2026-10-28
FAERS reports are unverified and do not prove the drug caused the event. Reporting rises with use, publicity and lawsuits, so these counts cannot give rates or risks and cannot be compared between drugs.
Recalls
FDA drug recalls naming naltrexone
FDA enforcement reports list 15 drug recall entries naming naltrexone from 2013 to 2022-06-15. 14 of them are for compounded or other unlisted products and 1 for products FDA lists under a label. The most common stated reason was lack of sterility assurance (5 of 15).
| Measure | Value | Note |
|---|---|---|
| Recall entries on record | 15 | |
| For products FDA lists under an approved or registered label | 1 | |
| For compounded or other unlisted products | 14 | matched by the name in the product description |
| Class I (most serious) | 0 | |
| Class II | 15 | |
| Class III | 0 | |
| Most recent recall reported | 2022-06-15 | |
| Most common stated reason | lack of sterility assurance | 5 of 15 entries |
How this was calculated
Counted enforcement report entries matched by FDA's listed active substance, or by the name in the product description where FDA lists none. Reasons were grouped by keywords in FDA's stated reason.
Recalls of single-ingredient naltrexone products, plus compounded or unlisted products whose description names it
Each recall covers specific lots from one firm and is not a statement about every product with this ingredient. One event can appear as several entries, one per product.
Clinical studies
Registered clinical studies of naltrexone
ClinicalTrials.gov lists 538 registered studies that name naltrexone as an intervention as of 2026-11-11. Of these, 30 are recruiting, 383 are completed and 103 are phase 3 studies.
| Measure | Value |
|---|---|
| Registered studies | 538 |
| Recruiting now | 30 |
| Not yet recruiting | 16 |
| Completed | 383 |
| Terminated, withdrawn or suspended | 63 |
| Phase 3 (including phase 2/3) | 103 |
| Phase 2 (including phase 1/2) | 155 |
| Phase 1 | 85 |
How this was calculated
Searched the ClinicalTrials.gov intervention field for the name, downloaded every matching record and counted by overall status and phase. Combined phases are counted under the higher phase. Phase not applicable covers observational, device and behavioural studies.
Studies whose intervention field matches naltrexone, any condition, any country, all statuses
A registered study is not a result. Counts include studies where the drug is a comparator or background treatment, and studies that never finished or reported.
Articles on Naltrexone
- Low-Dose Naltrexone Monitoring for Adults (30 to 49): Lab Schedule, Side Effects, and Follow-Up
- Low-Dose Naltrexone: Compounded vs Branded Comparison
- Low-Dose Naltrexone Manufacturing, Supply & Shortage History
- Low-Dose Naltrexone Monitoring Schedule: Labs & Exams Your Prescriber Should Order
- Low-Dose Naltrexone Off-Label Uses: Evidence Levels for Every Indication
- Low-Dose Naltrexone Patent Status and Generic Timeline