Introduction
Quercetin is a compound that gives plants and foods their color. It is found in onions, berries, and teas. Quercetin has been used to improve heart health and athletic performance. It has also been used as an antioxidant to help slow damage to cells. Quercetin can be taken as a pill or powder. It can also be injected into the bloodstream by a healthcare provider.
Dosages
500 milligrams 1 to 2 times daily
What Research Shows
Likely Effective
- High Blood Pressure —likely to lower blood pressure A1
- Metabolic syndrome —may lower fasting plasma glucose B1
May Be Effective
- Upper respiratory tract infection—may improve symptoms and promote quicker recovery C1
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.
Safety Notes
It is likely safe to take quercetin in small doses for a short time. Not enough studies have been done to say whether it is safe to take for a long period. It is also not known whether it is safe to take by women who are pregnant or breastfeeding. D1
Interactions
Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse.
References
REFA High Blood Pressure
REFA1 Serban MC, Sahebkar A, et al. Effects of Quercetin on Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Am Heart Assoc. 2016;5(7):e002713.
REFB Metabolic Syndrome
REFB1 Ostadmohammadi V, Milajerdi A, et al. Effects of quercetin supplementation on glycemic control among patients with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trials. Phytother Res. 2019 May;33(5):1330-1340.
REFC Upper Respiratory Tract Infection
REFC1 Heinz SA, Henson DA, et al. Quercetin supplementation and upper respiratory tract infection: A randomized community clinical trial. Pharmacol Res. 2010;62(3):237-242.
REFD Safety
REFD1 Andres S, Pevny S, et al. Safety Aspects of the Use of Quercetin as a Dietary Supplement. Mol Nutr Food Res. 2018 Jan;62(1).