Disease × agent evidence record

Metformin for Long COVID: evidence, trials and status

Metformin has both completed registered trials and synthesis-level publications linked to Long COVID. That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit.

3 registered trials 0 recruiting 23 publications Evidence tier B · Moderate Score 52.0
Research Tracker › Pairs › Long COVID › Metformin
Research map, not treatment advice. This page aggregates registry and literature records. It does not evaluate efficacy, dosing or safety for any individual. Discuss any treatment decision with a qualified clinician.

Summary

Metformin 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 ClinicalTrials.gov lists 3 registered trials linking Metformin to Long COVID: 2 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT04510194, sponsored by University of Minnesota). It plans or enrolled 1323 participants. Registration activity spans 2021 to 2024. The literature layer holds 23 publications for this pair: 4 systematic reviews, 4 clinical trial publications, 3 curated references and 12 other publications. The dated items are from 2025. Because at least one synthesis-level source exists (systematic review, meta-analysis or Cochrane review), this pair has been assessed beyond single studies, although the synthesis may concern a different indication.

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.

Open in Repurposing ExplorerAgent page: MetforminLong COVID hubLong COVID biomarkers & interventionsPubChem

Evidence table

Evidence tierB · Moderate
Evidence score52.0 (trials 12.0, literature 30.0, tier 10, approved bonus 0.0)
Registered trials3 total: 0 recruiting, 0 active / not yet recruiting, 2 completed, 1 other
Linked publications23 (12 other publications, 4 systematic reviews, 4 clinical trial publications, 3 curated references)
Agent typeDrug (Drug (Pharmaceutical))
Development stage (any indication)Investigational
Mechanism / classAnti-inflammatory; Metabolic / Mitochondrial
Data sourcesOSMF therapeutic agent database, ClinicalTrials.gov, PubMed
Also known asMetformin
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 IDTitleStatusPhaseEnrolment
NCT04510194COVID-OUT: Early Outpatient Treatment for SARS-CoV-2 Infection (COVID-19)
University of Minnesota · 2021
completedPhase 31,323
NCT06128967A Multicenter, Adaptive, Randomized, doublE-blinded, Placebo-controlled Study in Participants With Long COVID-19: The REVIVE Trial
Cardresearch · 2023
completedPhase 3399
NCT06147050Effect of Metformin in Reducing Fatigue in Long COVID in Adolescents
Purpose Life Sciences · 2024
status unknownPhase 316

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Published literature

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Mechanism and notes

Recorded mechanism or class: Anti-inflammatory; Metabolic / Mitochondrial.

Clinical notes: Prevention signal strong; treatment data mixed/preliminary. 500-2000mg. GI effects, B12. Reasonable metabolic adjunct in overweight PASC patients.

Safety: GI side effects (diarrhea, nausea) common initially. Risk of B12 deficiency long-term; lactic acidosis rare (avoid in severe renal/hepatic disease, contrast).

Dosing in studies: 500–2000 mg/day (extended release often better tolerated); prevention trials used during acute infection ~14 days; treatment studies 8–12+ weeks.

Frequently asked questions

Is Metformin approved for Long COVID?

Metformin 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 Metformin in clinical trials for Long COVID?

ClinicalTrials.gov lists 3 registered trials linking Metformin to Long COVID: 2 have completed; 1 is terminated, withdrawn, suspended or of unknown status. The most advanced is Phase 3 (NCT04510194, sponsored by University of Minnesota). It plans or enrolled 1323 participants. Registration activity spans 2021 to 2024.

What does the evidence show for Metformin in Long COVID?

Metformin has both completed registered trials and synthesis-level publications linked to Long COVID. That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit. OSMF's existing evidence tier for this pair is B (Moderate), 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

Open Source Medicine Foundation. Metformin for Long COVID: evidence, trials and status. OSMF Research Tracker. Updated 2026-10-07. https://research.opensourcemed.info/pairs/long-covid/metformin.html

Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-10-07. Page built 2026-10-07.

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This is a research map, not treatment advice. Evidence tiers and scores summarise what has been studied, not whether a treatment works or is safe for you.