Summary
Naltrexone is tracked by OSMF as an investigational option for Long COVID; no regulator has approved it for this indication, and most post-viral conditions have no approved disease-modifying therapy at all. ClinicalTrials.gov lists 1 registered trial linking Naltrexone to Long COVID: 1 has completed. The most advanced is Phase 2 (NCT04604704, sponsored by AgelessRx). It plans or enrolled 36 participants. Registered activity dates to 2021. The literature layer holds 2 publications for this pair: 2 curated references. The dated items are from 2026. Items here are search-derived or curated references rather than classified trial reports; treat them as leads to read, not as graded evidence.
Long COVID / PASC is tracked on the OSMF post-viral programme alongside ME/CFS, Long COVID, POTS and MCAS. Across the programme, 423 candidate agents are logged for Long COVID, most of them preliminary; this page isolates the record for one of them.
Evidence table
| Evidence tier | C · Preliminary |
|---|---|
| Evidence score | 11.5 (trials 3.5, literature 3.0, tier 5, approved bonus 0.0) |
| Registered trials | 1 total: 0 recruiting, 0 active / not yet recruiting, 1 completed, 0 other |
| Linked publications | 2 (2 curated references) |
| Agent type | Drug (Drug (Pharmaceutical)) |
| Development stage (any indication) | Investigational |
| Mechanism / class | Immunomodulatory; Repurposed Drug |
| Data sources | OSMF therapeutic agent database, ClinicalTrials.gov, PubMed |
| Also known as | Naltrexone |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT04604704 | Pilot Study Into LDN and NAD+ for Treatment of Patients With Post-COVID-19 Syndrome AgelessRx · 2021 | completed | Phase 2 | 36 |
Published literature
- Curated reference (OSMF) Low-Dose Naltrexone: What is the Evidence? A Narrative Review.2026
- Curated reference PubMed record PMID 42060160
Mechanism and notes
Recorded mechanism or class: Immunomodulatory; Repurposed Drug.
Clinical notes: Investigational for listed conditions. 1 associated trial(s) and 1 study reference(s) in current data. Review primary sources and consult specialists before use.
Safety: Limited specific safety data in these populations. Review full prescribing information and consult specialist. Many agents used off-label or investigational.
Dosing in studies: See linked studies/trials for reported doses and durations; typical protocols vary widely.
Frequently asked questions
Is Naltrexone approved for Long COVID?
Naltrexone is tracked by OSMF as an investigational option for Long COVID; no regulator has approved it for this indication, and most post-viral conditions have no approved disease-modifying therapy at all. Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Naltrexone in clinical trials for Long COVID?
ClinicalTrials.gov lists 1 registered trial linking Naltrexone to Long COVID: 1 has completed. The most advanced is Phase 2 (NCT04604704, sponsored by AgelessRx). It plans or enrolled 36 participants. Registered activity dates to 2021.
What does the evidence show for Naltrexone in Long COVID?
Naltrexone has 1 completed trial and 2 linked publications for Long COVID. Completed trials may or may not have posted results; follow the NCT links to check. OSMF's existing evidence tier for this pair is C (Preliminary), taken from the OSMF therapeutic agent database, which grades agents by the volume and design of condition-specific evidence rather than by effect size.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-10-07. Page built 2026-10-07.