deltatrials
Completed PHASE4 INTERVENTIONAL 2-arm NCT04809974

Clinical Trial of Niagen to Examine Recovery in People With Persistent Cognitive and Physical Symptoms After COVID-19

Randomized, Placebo-controlled Parallel Group Clinical Trial of Nicotinamide Riboside to Evaluate NAD+ Levels in Individuals With Persistent Cognitive and Physical Symptoms After COVID-19 Illness (Long-COVID)

Sponsor: Massachusetts General Hospital

Interventions Niagen
Updated 10 times since 2021 Last updated: Jul 21, 2025 Started: Aug 28, 2021 Primary completion: Oct 5, 2023 Completion: Feb 23, 2024
This information is for research purposes only and is not medical advice. Consult a healthcare provider before making any medical decision.

Listed as NCT04809974, this PHASE4 trial focuses on Cognitive Symptom and Covid19 and remains completed. Sponsored by Massachusetts General Hospital, it has been updated 10 times since 2021, reflecting substantial change activity. This study is part of the global effort to build evidence for infectious disease interventions.

Status Flow

~Apr 2021 – ~May 2021 · 30 days · monthly snapshotNot Yet Recruiting~May 2021 – ~Sep 2021 · 4 months · monthly snapshotNot Yet Recruiting~Sep 2021 – ~Sep 2022 · 12 months · monthly snapshotRecruiting~Sep 2022 – ~Apr 2024 · 19 months · monthly snapshotRecruiting~Apr 2024 – ~Jul 2024 · 3 months · monthly snapshotCompleted~Jul 2024 – ~Sep 2024 · 2 months · monthly snapshotCompleted~Sep 2024 – ~Jul 2025 · 10 months · monthly snapshotCompleted~Jul 2025 – ~Aug 2025 · 31 days · monthly snapshotCompleted~Aug 2025 – ~Sep 2025 · 31 days · monthly snapshotCompleted~Sep 2025 – present · 10 months · monthly snapshotCompleted

Change History

10 versions recorded
  1. Sep 2025 — Present [monthly]

    Completed PHASE4

  2. Aug 2025 — Sep 2025 [monthly]

    Completed PHASE4

  3. Jul 2025 — Aug 2025 [monthly]

    Completed PHASE4

  4. Sep 2024 — Jul 2025 [monthly]

    Completed PHASE4

  5. Jul 2024 — Sep 2024 [monthly]

    Completed PHASE4

Show 5 earlier versions
  1. Apr 2024 — Jul 2024 [monthly]

    Completed PHASE4

    Status: RecruitingCompleted

  2. Sep 2022 — Apr 2024 [monthly]

    Recruiting PHASE4

  3. Sep 2021 — Sep 2022 [monthly]

    Recruiting PHASE4

    Status: Not Yet RecruitingRecruiting

  4. May 2021 — Sep 2021 [monthly]

    Not Yet Recruiting PHASE4

  5. Apr 2021 — May 2021 [monthly]

    Not Yet Recruiting PHASE4

    First recorded

Eligibility Summary

No eligibility information available.

Contact Information

Sponsor contact:
  • Massachusetts General Hospital
Data source: Massachusetts General Hospital

For direct contact, visit the study record on ClinicalTrials.gov .

Study Locations