Trial reportInternational journal of general medicine2021
Possible Therapeutic Effects of Adjuvant Quercetin Supplementation Against Early-Stage COVID-19 Infection: A Prospective, Randomized, Controlled, and Open-Label Study.
Trial report in International journal of general medicine, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT05134766 (Retrospective Evaluation of Clinical, Virological and Serological Data in Patients With Mild Acute Upper Respiratory Tract Infections), which is not on this map. Cited by 106 papers, 4 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Retrospective Evaluation of Clinical, Virological and Serological Data in Patients With Mild Acute Upper Respiratory Tract Infections
Who cites it
106 citing papers in PubMed, 4 syntheses or guidelines pooled it, 181 citations in OpenAlex.
- Pneumolysin as a target for new therapies against pneumococcal infections: A systematic review.PloS one · 2023Pooled it
- A Review of In Silico Research, SARS-CoV-2, and Neurodegeneration: Focus on Papain-Like Protease.Neurotoxicity research · 2022Pooled it
- Flavonoids for Treating Viral Acute Respiratory Tract Infections: A Systematic Review and Meta-Analysis of 30 Randomized Controlled Trials.Frontiers in public health · 2022Pooled it
- Characteristics of published/registered clinical trials on COVID-19 treatment: A systematic review.Daru : journal of Faculty of Pharmacy, Tehran University of Medical Sciences · 2021Pooled it
- FermentedNutrients · 2022Trial
- The therapeutic efficacy of quercetin in combination with antiviral drugs in hospitalized COVID-19 patients: A randomized controlled trial.European journal of pharmacology · 2022Trial
- Potential Clinical Benefits of Quercetin in the Early Stage of COVID-19: Results of a Second, Pilot, Randomized, Controlled and Open-Label Clinical Trial.International journal of general medicine · 2021Trial
- Research progress of quercetin in infection at the maternal-fetal interface.Frontiers in immunology · 2026Review
- Structure-activity relationships and molecular mechanisms of natural products in sepsis-associated organ dysfunction: a narrative review.Frontiers in pharmacology · 2026Review
- The Effects of Quercetin on Vascular Endothelium, Inflammation, Cardiovascular Disease and Lipid Metabolism-A Review.Nutrients · 2025Review
- Quercetin and Its Lecithin-Based Formulation: Potential Applications for Allergic Diseases Based on a Narrative Review.Nutrients · 2025Review
- Goutweed (Molecules (Basel, Switzerland) · 2025Review
- Immunosenescence promotes cancer development: from mechanisms to treatment strategies.Cell communication and signaling : CCS · 2025Review
- [Mechanism and significance of cell senescence induced by viral infection].Zhejiang da xue xue bao. Yi xue ban = Journal of Zhejiang University. Medical sciences · 2025Review
- Targeting SIRT1: A Potential Strategy for Combating Severe COVID-19.BioMed research international · 2025Review
- Innovative Approaches in Molecular Docking for the Discovery of Novel Inhibitors Against Alzheimer's Disease.Current Alzheimer research · 2025Review
- Flavonoid compound fromFrontiers in cellular and infection microbiology · 2025Article
- Phytosomes-Unraveling the Unique Properties of Plant-Derived Nanotechnological Drug Delivery Systems: A Review.Current medicinal chemistry · 2025Review
- Potential pharmacological effect of Quercetin Phytosome™ in the management of hyperuricemia: results from real-life clinical studies.Frontiers in nutrition · 2025Article
- Simple preparation and greatly improved oral bioavailability: The supersaturated drug delivery system of quercetin based on PVP K30.Drug delivery and translational research · 2024Article
46 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
19 authors at 8 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundQuercetin, a well-known naturally occurring polyphenol, has recently been shown by molecular docking, in vitro and in vivo studies to be a possible anti-COVID-19 candidate. Quercetin has strong antioxidant, anti-inflammatory, immunomodulatory, and antiviral properties, and it is characterized by a very high safety profile, exerted in animals and in humans. Like most other polyphenols, quercetin shows a very low rate of oral absorption and its clinical use is considered by most of modest utility. Quercetin in a delivery-food grade system with sunflower phospholipids (Quercetin Phytosome
methodsIn the present prospective, randomized, controlled, and open-label study, a daily dose of 1000 mg of QP was investigated for 30 days in 152 COVID-19 outpatients to disclose its adjuvant effect in treating the early symptoms and in preventing the severe outcomes of the disease.
resultsThe results revealed a reduction in frequency and length of hospitalization, in need of non-invasive oxygen therapy, in progression to intensive care units and in number of deaths. The results also confirmed the very high safety profile of quercetin and suggested possible anti-fatigue and pro-appetite properties.
conclusionQP is a safe agent and in combination with standard care, when used in early stage of viral infection, could aid in improving the early symptoms and help in preventing the severity of COVID-19 disease. It is suggested that a double-blind, placebo-controlled study should be urgently carried out to confirm the results of our study.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.