Quercetin’s benefits and effects include relieving cough and phlegm, anti-inflammatory and anti-allergy, cancer prevention and anti-cancer, as described below. 1. Relieving cough and phlegm: It can relieve cough and asthma by relaxing bronchial smooth muscle, and increase the movement of tracheal cilia to promote the discharge of phlegm. 2. Anti-inflammatory and anti-allergic: it can inhibit cellular lipoxygenase and cyclooxygenase, reduce the generation of leukotrienes and prostaglandins, thus exerting anti-inflammatory and anti-allergic effects. 3. Anti-cancer and anti-cancer: Quercetin is a flavonol compound with a variety of biological activities, with potential chemopreventive activity, which can help inhibit cell proliferation and mutation, and play the role of anti-cancer and anti-cancer. Immediately rinse with plenty of soapy water after inadvertent skin contact with quercetin. It is toxic in large quantities. It is prohibited for those who are allergic to quercetin. Side effects such as nausea, vomiting and difficulty in breathing may occur when taking Quercetin. Quercetin is currently used as an adjunctive medication. If you suffer from related diseases, you should choose the most suitable therapeutic drug under the guidance of your doctor.