Quercetin supplements are frequently used to provide antihistamine, anti-inflammatory and anti-allergy benefits. In vitro, quercetin has been shown to help stabilize mast cells, a type of immune cell involved in histamine release and the inflammation response. Quercetin helps to inhibit the synthesis of enzymes that regulate histamine release and degranulation. For this reason, quercetin may be useful in helping to provide relief from allergies.
Quercetin also is being studied for its potential benefits to gut health, since mast cell activation has been associated with irritable and inflammatory gastrointestinal disorders. In general, quercetin may help to support a healthy inflammatory response by reducing the production of prostaglandins and leukotrienes, compounds that promote inflammation throughout the body.