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Other Treatments Global Adoption
Quercetin for COVID-19
10 studies from 101 scientists
1,387 patients in 6 countries
Statistically significant improvement for ICU, hospitalization, recovery, cases, and viral clearance.
44% improvement in 9 RCTs CI [15-64%]
Studies typically use advanced formulations for greatly improved bioavailability.
COVID-19 Quercetin studies. Jun 2023.
0 0.5 1 1.5+ All studies 50% With exclusions 42% Mortality 59% Hospitalization 68% Recovery 34% Cases 93% Viral clearance 56% RCTs 44% RCT mortality 59% Prophylaxis 93% Early 32% Late 31% Favorsquercetin Favorscontrol
Quercetin COVID-19 studies. Studies typically use advanced formulations for greatly improved bioavailability. Recent:
Massimo Magro
Quercetin has been officially adopted in part of 1 country. Submit updates/corrections.
Jun 3
Covid Analysis (Preprint) (meta analysis) Quercetin for COVID-19: real-time meta analysis of 10 studies
Statistically significant improvements are seen for ICU admission, hospitalization, recovery, cases, and viral clearance. 9 studies from 7 independent teams in 6 different countries show statistically significant improvements in isolati..
May 15
Massimo Magro et al., Journal of Modern Biology and Drug Discovery, doi:10.53964/jmbdd.2023004 (Review) Use of Quercetin for Therapeutic Purposes in COVID-19 Infections: The Opinion of the Geriatrician Doctor
Review of the antiviral properties and potential benefits of quercetin for COVID-19.
Apr 24
Xu et al., Proceedings of the National Academy of Sciences, doi:10.1073/pnas.2301775120 (In Vitro) Bioactive compounds from Huashi Baidu decoction possess both antiviral and anti-inflammatory effects against COVID-19
In Vitro study of compounds from Huashi Baidu (Q-14), showing dose-dependent inhibition of SARS-CoV-2 with quercetin. Authors also perform a mouse study showing that Q-14 decreases SARS-CoV-2 viral load and reduces pulmonary inflammation...
Mar 31
Wang et al., Society of Toxicology Conference, 2023 Computational Analysis of Lianhua Qingwen as an Adjuvant Treatment in Patients with COVID-19
In Silico analysis of components of Lianhua Qingwen, identifying quercetin, luteolin, wogonin, and phillyrin as potentially beneficial for COVID-19. Authors note that quercetin bound to Mpro at the same inhibitory pocket as nirmatrelvir (..
Mar 22
Ibeh et al., Informatics in Medicine Unlocked, doi:10.1016/j.imu.2023.101230 Computational studies of potential antiviral compounds from some selected Nigerian medicinal plants against SARS-CoV-2 proteins
In Silico study identifying quercetin and naringenin as potent multitarget-directed ligands for 3CLpro, PLpro, and ACE2 with favorable ADME properties.
Feb 13
Cheema et al., Reviews in Medical Virology, doi:10.1002/rmv.2427 (meta analysis) Quercetin for the treatment of COVID-19 patients: A systematic review and meta-analysis
Systematic review and meta analysis of 6 quercetin RCTs, showing significantly lower hospitalization and ICU admission. Differences for mortality and recovery were not statistically significant.
Jan 26
Pastor-Fernández et al., Aging Cell, doi:10.1111/acel.13771 Treatment with the senolytics dasatinib/quercetin reduces SARS-CoV-2 related mortality in mice
K18-hACE2 mouse study showing reduced COVID-19 severity with quercetin and dasatinib, for both prophylaxis and early treatment.
Jan 25
Turobkulovich et al., Emergent: Journal of Educational Discoveries and Lifelong Learning Applications of quercetin for the prevention of COVID-19 in healthcare workers
96% lower mortality [p<0.0001] and 98% fewer symptomatic cases [p<0.0001]. Prospective study of healthcare workers in Uzbekistan showing lower mortality and cases with quercetin prophylaxis. Very minimal details are provided, there is no baseline information, and control mortality is very high.
Jan 18
Aguado et al., bioRxiv, doi:10.1101/2023.01.17.524329 (Preprint) Senolytic therapy alleviates physiological human brain aging and COVID-19 neuropathology
In Vitro and animal study showing that senolytics including dasatinib + quercetin improve survival and mitigate neuropathological sequelae of SARS-CoV-2. Authors show that SARS-CoV-2 can initiate cellular senescence in the brains of COVID..
Jan 18
Din Ujjan et al., Frontiers in Nutrition, doi:10.3389/fnut.2022.1023997 The possible therapeutic role of curcumin and quercetin in the early-stage of COVID-19—Results from a pragmatic randomized clinical trial
29% improved recovery [p=0.11] and 91% improved viral clearance [p=0.05]. Small RCT with 50 outpatients, 25 treated with curcumin, quercetin, and vitamin D, showing improved recovery and viral clearance with treatment. 168mg curcumin, 260mg, 360IU vitamin D3 daily for 14 days.
Jan 17
Shorobi et al., Molecules, doi:10.3390/molecules28030938 (Review) Quercetin: A Functional Food-Flavonoid Incredibly Attenuates Emerging and Re-Emerging Viral Infections through Immunomodulatory Actions
Review of the antiviral properties of quercetin and derivatives, and potential mechanisms of action.
Jan 16
Viglione et al., The Gazette of Medical Sciences, doi:10.46766/thegms.pubheal.22120905 Intravenous high dose vitamin C and ozonated saline effective treatment for Covid -19: The Evolution of Local Standard of Care
Retrospective 479 high risk outpatients in the USA treated with a protocol including intravenous vitamin C, vitamin D, zinc, quercetin, bromelain, lactoferrin, HCQ, ivermectin, ozonated saline, azithromycin, ceftriaxone, methylprednisolon..
Jan 13
Di Pierro et al., Frontiers in Pharmacology, doi:10.3389/fphar.2022.1096853 Quercetin as a possible complementary agent for early-stage COVID-19: Concluding results of a randomized clinical trial
37% improved recovery [p=0.007] and 58% improved viral clearance [p<0.0001]. RCT 100 outpatients in Pakistan, 50 treated with quercetin phytosome, showing faster viral clearance and improved recovery with treatment. Patients in the treatment group were significantly younger (41 vs. 54).
Jan 12
Nguyen et al., Bioinformatics and Biology Insights, doi:10.1177/11779322221149622 The Potential of Ameliorating COVID-19 and Sequelae From Andrographis paniculata via Bioinformatics
In Silico study of components of andrographis paniculata, identifying multiple components including quercetin as promising inhibitors of SARS-CoV-2. Authors note the potential synergistic effect with multiple compounds.
Dec 12
Wu et al., Molecular Therapy, doi:10.1016/j.ymthe.2022.12.002 Treatment with Quercetin inhibits SARS-CoV-2 N protein-induced acute kidney injury by blocking Smad3-dependent G1 cell cycle arrest
Mouse study showing quercetin can significantly inhibit SARS-CoV-2 induced acute kidney injury via blocking of SARS-CoV-2 N-Smad3-mediated cell death.
Nov 29
Alavi et al., Biomedicines, doi:10.3390/biomedicines10123074 Interaction of Epigallocatechin Gallate and Quercetin with Spike Glycoprotein (S-Glycoprotein) of SARS-CoV-2: In Silico Study
In Silico study suggesting efficacy of epigallocatechin gallate and quercetin for SARS-CoV-2.
Oct 18
Cosentino et al., Journal of Clinical Medicine, doi:10.3390/jcm11206138 Early Outpatient Treatment of COVID-19: A Retrospective Analysis of 392 Cases in Italy
Retrospective 392 outpatients in Italy showing 0.2% mortality with early treatment, compared with >3% in Italy at the time. Treatment varied for individual patients and included HCQ, vitamin D, vitamin C, vitamin A, zinc, quercetin, bromh..
Aug 25
Gasmi et al., Pharmaceuticals, doi:10.3390/ph15091049 (Review) Quercetin in the Prevention and Treatment of Coronavirus Infections: A Focus on SARS-CoV-2
Review of the potential benefits of quercetin for COVID-19, including inhibitory effects on several stages of the viral life cycle, antioxidant, anti-inflammatory, and immunomodulatory effects, and synergistic effects with other treatments.
Aug 10
Chellasamy et al., Journal of King Saud University - Science, doi:10.1016/j.jksus.2022.102277 Docking and molecular dynamics studies of human ezrin protein with a modelled SARS-CoV-2 endodomain and their interaction with potential invasion inhibitors
In Silico study of SARS-CoV-1&2 endodomains and ezrin docking, identifying ivermectin, quercetin, calcifediol, calcitriol, selamectin, and minocycline as potential therapeutic drugs with strong ezrin binding which may restrict viral endod..
Jun 16
Ortore et al., International Journal of Translational Medicine, doi:10.3390/ijtm2020022 Evaluation of the Clinical Effects of an Antiviral, Immunostimulant and Antioxidant Phytotherapy in Patients Suffering from COVID-19 Infection: An Observational Pilot Study
Retrospective case series of 240 patients in Italy in 2020, up to 96 years old, showing no mortality and 1.6% hospitalization with early treatment including vitamin C, quercetin, and green tea and red wine polyphenols. The formulation was..
May 20
Shah et al., medRxiv, doi:10.1101/2022.05.16.22275074 (Preprint) Jinhua Qinggan Granules for Nonhospitalized COVID-19 Patients: a Double-Blind, Placebo-Controlled, Randomized Controlled Trial
81% greater improvement [p<0.0001] and 8% worse viral clearance [p=0.48]. RCT 300 outpatients in China, showing improved recovery with Jinhua Qinggan treatment, but no significant difference in viral clearance or radiographic findings. Jinhua Qinggan includes quercetin, rutin, luteolin, wogonin, myricetin, urso..
May 15
Rizky et al., Life Research, doi:10.53388/life2022-0205-302 (Review) The pharmacological mechanism of quercetin as adjuvant therapy of COVID-19
Review of in silico and clinical evidence supporting the use of quercetin for COVID-19.
May 1
Khan et al., Frontiers in Pharmacology, doi:10.3389/fphar.2022.898062 Oral Co-Supplementation of Curcumin, Quercetin, and Vitamin D3 as an Adjuvant Therapy for Mild to Moderate Symptoms of COVID-19—Results From a Pilot Open-Label, Randomized Controlled Trial
33% improved recovery [p=0.15] and 50% improved viral clearance [p=0.009]. RCT 50 COVID+ outpatients in Pakistan, 25 treated with curcumin, quercetin, and vitamin D, showing significantly faster viral clearance, significantly improved CRP, and faster resolution of acute symptoms (p=0.154). 168mg curcumin, 260mg ..
Apr 29
Imran et al., Antioxidants, doi:10.3390/antiox11050876 (Review) The Therapeutic and Prophylactic Potential of Quercetin against COVID-19: An Outlook on the Clinical Studies, Inventive Compositions, and Patent Literature
Review of the evidence supporting the use of quercetin for COVID-19 from clinical studies and patents.
Jan 21
Goc et al., European Journal of Microbiology and Immunology, doi:10.1556/1886.2021.00022 (In Vitro) Inhibitory effects of specific combination of natural compounds against SARS-CoV-2 and its Alpha, Beta, Gamma, Delta, Kappa, and Mu variants
In Vitro study testing combinations of plant extracts and micronutrients with several variants of SARS-CoV-2. A combination of vitamin C, N-acetylcysteine, curcumin, quercetin, resveratrol, theaflavin, naringenin, baicalin, and broccoli e..
Jan 4
Rondanelli et al., Life, doi:10.3390/life12010066 Promising Effects of 3-Month Period of Quercetin Phytosome® Supplementation in the Prevention of Symptomatic COVID-19 Disease in Healthcare Workers: A Pilot Study
93% fewer symptomatic cases [p=0.04]. RCT 120 healthcare workers, 60 treated with quercetin phytosome, showing lower risk of cases with treatment. Quercetin phytosome 250mg twice a day.
Dec 28
Munafò et al., Research Square, doi:10.21203/ (Preprint) (In Vitro) Quercetin and Luteolin Are Single-digit Micromolar Inhibitors of the SARS-CoV-2 RNA-dependent RNA Polymerase
In Vitro and In Silico study showing quercetin and luteolin inhibiting SARS-CoV-2 RNA-dependent RNA polymerase (RdRp).
Dec 14
Singh et al., Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, doi:10.1016/j.bbadis.2021.166322 (In Vitro) The spike protein of SARS-CoV-2 virus induces heme oxygenase-1: Pathophysiologic implications
In Vitro study transfecting SARS-CoV-2 viral spike protein in kidney cell lines, showing syncytia formation and upregulation of the cytoprotective gene HO-1, and that quercetin, which induces HO-1, can reduce syncytia formation. Authors c..
Dec 8
Fazio et al., Medical Science Monitor, doi:10.12659/MSM.935379 Retrospective Study of Outcomes and Hospitalization Rates of Patients in Italy with a Confirmed Diagnosis of Early COVID-19 and Treated at Home Within 3 Days or After 3 Days of Symptom Onset with Prescribed and Non-Prescribed Treatments Between November 2020 and August 2021
Retrospective 158 COVID-19 patients in Italy treated with hesperidin, quercetin, indomethacin, aspirin, omeprazole, azithromycin, LMWH, and betamethasone (treatment specific for each patient), showing significantly lower hospitalization a..
Dec 2
Shohan et al., European Journal of Pharmacology, doi:10.1016/j.ejphar.2021.1746158 The therapeutic efficacy of quercetin in combination with antiviral drugs in hospitalized COVID-19 patients: A randomized controlled trial
86% lower mortality [p=0.24] and 32% faster recovery [p=0.04]. Small RCT with 60 severe hospitalized patients in Iran, 30 treated with quercetin, showing shorter time until discharge. All patients received remdesivir or favipiravir, and vitamin C, vitamin D, famotidine, zinc, dexamethasone, and magne..
Nov 14
Bahun et al., Food Chemistry, doi:10.1016/j.foodchem.2021.131594 (In Vitro) Inhibition of the SARS-CoV-2 3CLpro main protease by plant polyphenols
In Silico and In Vitro study of plant polyphenols identifying quercetin, curcumin, ellagic acid, epigallocatechin gallate and resveratrol as SARS-CoV-2 3CLpro inhibitors with IC50 between 11.8µM and 23.4µM. Real-time binding was analyzed..
Sep 29
Şimşek et al., Journal of Molecular Graphics and Modelling, doi:10.1016/j.jmgm.2021.108038 In silico identification of SARS-CoV-2 cell entry inhibitors from selected natural antivirals
In Silico study identifying quercetin derivatives as SARS-CoV-2 spike protein, ACE2, and neuropilin inhibitors.
Sep 1
Zupanets et al., Zaporozhye Med. J., doi:10.14739/2310-1210.2021.5.231714 Quercetin effectiveness in patients with COVID-19 associated pneumonia
29% improved recovery [p=0.5]. RCT 200 patients in Ukraine, 99 treated with IV quercetin/polyvinylirolidone followed by oral quercetin/pectin, showing improved recovery with treatment.
Jul 6
Margolin et al., Journal of Evidence-Based Integrative Medicine, doi:10.1177/2515690X211026193 20-Week Study of Clinical Outcomes of Over-the-Counter COVID-19 Prophylaxis and Treatment
94% fewer cases [p=0.003]. Retrospective 113 outpatients, 53 (patient choice) treated with zinc, quercetin, vitamin C/D/E, l-lysine, and quina, showing lower cases with treatment. Results are subject to selection bias and limited information on the groups is provid..
Jun 15
Kandeil et al., Pathogens, doi:10.3390/pathogens10060758 (In Vitro) Bioactive Polyphenolic Compounds Showing Strong Antiviral Activities against Severe Acute Respiratory Syndrome Coronavirus 2
Vero E6 In Vitro study showing curcumin, hesperidin, and quercetin significantly inhibited SARS-CoV-2 replication, and In Silico analysis with promising Mpro and spike docking results.
Jun 8
Di Pierro et al., International Journal of General Medicine, doi:10.2147/IJGM.S318720 Possible Therapeutic Effects of Adjuvant Quercetin Supplementation Against Early-Stage COVID-19 Infection: A Prospective, Randomized, Controlled, and Open-Label Study
86% lower mortality [p=0.25], 94% lower ICU admission [p=0.006], and 68% lower hospitalization [p=0.003]. RCT 152 outpatients in Pakistan, 76 treated with quercetin phytosome, showing lower mortality, ICU admission, and hospitalization with treatment.
Apr 8
Aguilar et al., Journal of Advances in Medical and Pharmaceutical Sciences, doi:10.9734/jamps/2021/v23i330222 Oral Quercetin in Adult Patients as a Potential Nutraceutical against Coronavirus Disease 2019 (COVID-19)
Prospective study of 52 patients treated with quercetin. There was no control group.
Jan 19
Onal et al., Turk. J. Biol., 45:518-529 (date from earlier preprint) Treatment of COVID-19 patients with quercetin: a prospective, single center, randomized, controlled trial
94% lower ICU admission [p=0.39] and 78% higher hospital discharge [p=0.1]. RCT 447 moderate-to-severe hospitalized patients in Turkey, 52 treated with quercetin, bromelain, and vitamin C, showing no statistically significant difference in clinical outcomes. NCT04377789.
Nov 16
Arslan et al., SSRN, doi:10.2139/ssrn.3682517 (Preprint) Synergistic Effect of Quercetin and Vitamin C Against COVID-19: Is a Possible Guard for Front Liners
92% fewer cases [p=0.03]. Small prophylaxis RCT with 113 patients showing fewer cases with quercetin + vitamin C + bromelain prophylaxis. NCT04377789. Note that this paper disappeared from SSRN without explanation.
Oct 9
Derosa et al., Phytotherapy Research, doi:10.1002/ptr.6887 (Review) A role for quercetin in coronavirus disease 2019 (COVID-19)
Review noting that quercetin has a theoretical, but significant, capability to interfere with SARS-CoV-2 replication, with results showing this to be the fifth best compound out of 18 candidates.
Jun 19
Biancatelli et al., Frontiers in Immunology, doi:10.3389/fimmu.2020.01451 (Review) Quercetin and Vitamin C: An Experimental, Synergistic Therapy for the Prevention and Treatment of SARS-CoV-2 Related Disease (COVID-19)
Review of the evidence for the use of vitamin C and quercetin both for prophylaxis in high-risk populations and for the treatment of COVID-19 patients.
Apr 24
Sekiou et al., ChemRxiv, doi:10.26434/chemrxiv.12181404.v1 (Preprint) In-Silico Identification of Potent Inhibitors of COVID-19 Main Protease (Mpro) and Angiotensin Converting Enzyme 2 (ACE2) from Natural Products: Quercetin, Hispidulin, and Cirsimaritin Exhibited Better Potential Inhibition than Hydroxy-Chloroquine Against COVID-19 Main Protease Active Site and ACE2
In Silico study of natural compounds identifying quercetin, curcumin, hispidulin, cirsimaritin, sulfasalazine, and artemisin as potential compounds that inhibit SARS-CoV-2.
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