Synopsis

Source of validity: Scientific
Rating (out of 5): 2

Quercetin is a flavonoid found in many fruits and vegetables and has attracted scientific interest for its potential role in supporting immune health and reducing symptoms of the common cold. Several in vitro and animal studies have indicated that quercetin possesses antiviral, anti-inflammatory, and antioxidant properties, which might theoretically help reduce the severity or duration of colds. Quercetin is thought to block the replication of certain viruses and modulate the immune response, partly by inhibiting the release of histamine and cytokines. A few small human clinical trials have investigated the effects of quercetin supplementation on upper respiratory tract infections (URTIs), including the common cold. For example, a 2010 randomized controlled trial by Heinz et al. found that quercetin supplementation did not significantly reduce the incidence of URTIs overall but showed a potential benefit in specific subgroups, such as older, physically fit individuals. Other studies have reported modest reductions in the duration or severity of cold symptoms, but results are inconsistent and often limited by small sample sizes and methodological issues. In summary, while there is some scientific rationale and preliminary evidence supporting the use of quercetin for colds, the clinical evidence is limited and not robust. More large-scale, high-quality human trials are needed to establish its efficacy for this use. Therefore, its use is based on scientific principles and early research, but the strength of the evidence remains low.

More about quercetin
More about Colds (general)

Other ingredients used for Colds (general)

Other health conditions supported by quercetin

Products containing quercetin

Pure Encapsulations Acerola/Flavonoid
Thorne Advanced Nutrients Multivitamin
Pure Encapsulations AI Formula
Pure Encapsulations Aller-Essentials
Pure Encapsulations Aller-Essentials
Designs For Health ArthroSoothe™ Supreme
Pure Encapsulations Athletic Nutrients
Pure Encapsulations Balanced Immune
Designs For Health BioFizz® Immune
Metagenics CardioLux® HDL
Designs For Health C+BioFizz®
Douglas Laboratories Cysto Renew ®
Pure Encapsulations Daily Immune
Integrative Therapeutics Detoxication Factors
Integrative Therapeutics Detoxication Factors
Designs For Health DFH Complete Multi™
Designs For Health DFH Complete Multi™ with Copper
Designs For Health DFH Complete Multi™ with Copper & Iron
Thorne Diabenil
Designs For Health DopaBoost™
Designs For Health Electrolyte Synergy™
Pure Encapsulations Essential-C & Flavonoids
Pure Encapsulations Essential-C & Flavonoids
Designs For Health GI Revive®
Designs For Health GI Revive®
Designs For Health H-S-N Radiance™
Pure Encapsulations Hist Reset
Designs For Health HistaEze™
Metagenics Immune Active
Metagenics Immune Defense Pack
Designs For Health Inflammatone™
Designs For Health Inflammatone™
Designs For Health Inflammatone™
Vitabase Life's Essentials Plus
Metagenics Multigenics®
Metagenics Multigenics Chewable Orange
Metagenics Multigenics Intensive Care
Metagenics Multigenics Intensive Care without Iron
Metagenics Multigenics without Iron
Pure Encapsulations NeuroMood Pure Pack
Pure Encapsulations NeuroPure
Designs For Health OcuForce™
Designs For Health PaleoCleanse Plus™
Designs For Health PaleoCleanse Plus™
Designs For Health PaleoCleanse Plus™ Detox Program
Designs For Health PaleoCleanse Plus™Chocolate Detox Kit
Designs For Health PhytoBiome™
Metagenics PhytoGanix® Tropical Fruit
Designs For Health Plant Protein Cleanse
Designs For Health Plant Protein Cleanse Plus™ 570g
Pure Encapsulations Polyphenol Nutrients
Pure Encapsulations Polyphenol Nutrients
Thorne PolyResveratrol-SR
Designs For Health Primal Multi™
Vitabase Prostate Complex (Formerly Prostate Complete)
Pure Encapsulations PureDefense
Pure Encapsulations PureDefense with NAC
Pure Encapsulations PureDefense with NAC
Pure Encapsulations PureLean® Protein
Pure Encapsulations Quercetin
Pure Encapsulations Quercetin
Metagenics Quercetin 500
Vitabase Quercetin Plus
Designs For Health Quercetin-Ascorbate
Douglas Laboratories Quercetin-Bromelain Complex
Thorne Quercetin Complex Quercenase
Designs For Health Quercetin + Nettles
Thorne Quercetin Phytosome
Pure Encapsulations Quercetin UltraSorb
Thorne ResveraCel
Designs For Health Resveratrol Supreme
Designs For Health Senolytic Synergy
Metagenics Sinuplex®
Designs For Health Stellar C™
Vitabase Super Antioxidant Formula
Pure Encapsulations Th2 Modulator
Designs For Health Ultimate Antiox Full Spectrum
Douglas Laboratories Ultra Preventive
Douglas Laboratories Ultra Preventive
Douglas Laboratories Ultra Preventive ®-EZ Swallow
Douglas Laboratories Ultra Preventive® X
Douglas Laboratories Ultra Protein Green
Metagenics UltraInflamX Plus 360°® Chocolate/Orange
Metagenics UltraInflamX Plus 360° Mango
Metagenics UltraInflamX Plus 360° Mango
Metagenics UltraInflamX Plus 360° Orange
Metagenics UltraInflamX Plus 360° Original Spice
Metagenics UltraInflamX Plus 360° Pineapple/Banana
Metagenics UltraInflamX Plus 360° Pineapple/Banana
Pure Encapsulations Uric Acid Formula
Designs For Health Vessel Forte™
Vitabase Vision Support
Integrative Therapeutics Vitamin C with Quercetin