Publication date: Jul 16, 2026
Long covid is a debilitating chronic condition, and the effect of low-dose naltrexone (LDN) on its symptoms is unclear. We aimed to determine the effectiveness of LDN on symptoms of long covid. Systematic review and meta-analysis. PubMed, Embase and Cochrane Library for published studies; ClinicalTrials. gov and WHO International Clinical Trials Registry Platform (ICTRP) for registered ongoing studies were searched through 5 May 2026. We included randomised controlled trials and pre-post studies of patients with long covid reporting on fatigue, quality of life, cognitive symptoms or function and other long covid symptoms. Two independent reviewers used standardised methods to search, screen and select included studies. Risk of bias was assessed using the Newcastle-Ottawa Scale. Meta-analysis was conducted using random effects models. Of 397 titles and abstracts screened, no randomised controlled trials were identified. Four observational pre-post studies from the USA and Ireland (n=155) met inclusion criteria. LDN doses varied from 1 mg/day to 6 mg/day. Pooled pre-post analyses showed moderate effects for reducing fatigue (Hedges’ g=-0. 74; 95% CI -1. 11 to -0. 37; p
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Semantics
| Type | Source | Name |
|---|---|---|
| drug | DRUGBANK | Naltrexone |
| disease | MESH | long COVID |
| disease | MESH | chronic condition |
| disease | MESH | included |
| disease | MESH | fatigue |
| disease | MESH | cognitive symptoms |
| drug | DRUGBANK | Methionine |
| disease | MESH | COVID-19 |