Combined Metabolic Activators Accelerates Recovery in Mild-to-Moderate COVID-19, Altay et al, 28 June 2021

I don't know if Long COVID is the correct forum to put this in, since the study was about recovery from acute COVID. But I think it's possible that something that helps people recover from the acute disease could help with LC.

Study

 

At least two trials are testing nicotinamide riboside (one of the chemicals in the treatment) in long COVID:

Clinical Trial of Niagen to Examine Recovery in People With Persistent Cognitive and Physical Symptoms After COVID-19 Illness (Long-COVID)
- Study completed 2024-02-23

Mental Intervention and Nicotinamide Riboside Supplementation in Long Covid (MINIRICO)
- Recruiting (Lørenskog, Norway), estimated study completion 2025-01

 

RC controlled studies with administration of NAC are always avoided because no patent profit will be acquired.
But a lot of earlier cohort studies showed benefit of N-acetylcysteine (NAC) in acute COVID [1-Alam 2023- PMID: 37534078] .
Antiviral H2S in particular has multiple targets for SRS-C0V2 infection [2,3], whereby an acute
decrease of H2S in the airway epithelium also appears to occur. Administration of N-acetylcysteine (NAC) can
supplement this H2S deficiency [2,3 ], which also involves recovery of the lymphopenia, which is seen as a poor
prognosis [4].
Despite older age and more comorbidity, there was significantly less mortality with NAC in a very large cohort
study [5], for which a ratio had previously been described [6,7]. The earlier NAC is administered, the better the
antiviral effect [8]; even the timing for medication could already be determined before the appearance of viral
symptoms. In case of problematic or pandemic corona mutations, RC controlled administration of NAC is
indicated pending the development of adequate vaccines.

===-References-===
[1]-Alam MS, Hasan MN, Maowa Z, Khatun F, Nazir KHMNH, Alam MZ. N-acetylcysteine reduces severity and
mortality in COVID-19 patients: a systematic review and meta-analysis. J Adv Veterinarian Anim Res. June 30,
2023;10(2):157-168. doi:10.5455/javar.2023.j665. PMID: 37534078; PMCID: PMC10390689..
[2]-Bourgonje AR, Offringa AK, van Eijk LE, Abdulle AE, Hillebrands JL, van der Voort PHJ, van Goor H, van
Hezik EJ. N-Acetylcysteine and hydrogen sulfide in coronavirus disease 2019. Antioxidation redox signal. 2021
Nov 10;35(14):1207-1225. doi: 10.1089/ars.2020.8247. Epub Mar 25 2021. PMID: 33607929.
[3]-Yang G. H2S as a potential defense against COVID-19? Ben J Physiol Cell Physiol. August 1,
2020;319(2):C244-C249. doi: 10.1152/ajpcell.00187.2020. Epub 2020 June 9. PMID: 32515982; PMCID:
PMC7381713.
[4]-Prabowo NA, Megantara MA, Apriningsih H. The role of N-acetylcysteine in decreasing neutrophil-lymphocyte
ratio in COVID-19 patients: A double-blind, randomized controlled trial. Narra J 2023 Aug;3(2):e121. doi:
10.52225/narraj.v3i2.121. Epub 2023 May 19. PMID: 38454976; PMCID: PMC10919724.
[5] -Izquierdo-Alonso JL, Pérez-Rial S, Rivera CG, Peces-Barba G. N-acetylcysteine for the prevention and
treatment of COVID-19: current state of evidence and future directions. J Infect public health. 2022
Dec;15(12):1477-1483. doi: 10.1016/j.jiph.2022.11.009. Epub Nov 12 2022. PMID: 36410267; PMCID:
PMC9651994.
[6] -De Flora S, Balansky R, La Maestra S. Rationale for the use of N-acetylcysteine in both prevention and
adjuvant therapy of COVID-19. FASEB J. 2020 Oct;34(10):13185-13193. doi: 10.1096/fj.202001807. Epub 2020
Aug 11. PMID: 32780893; PMCID: PMC7436914.
[7]-Shi Z, Puyo CA. N-Acetylcysteine to Combat COVID-19: An Evidence Review. Ther Clin Risk Management.
2020 Nov 2;16:1047-1055. doi: 10.2147/TCRM.S273700. PMID: 33177829; PMCID: PMC7649937.
[8]-Protecting Patients from Viral Respiratory Infections, Correspondence Regarding Klompas et al., NEJM June
14, 2023, preprint, https://doi.org/10.21467/preprints.462