Quercetin for Seasonal Allergies

A 2022 study found that 200mg of quercetin daily significantly improved seasonal allergy symptoms compared to placebo over 4 weeks. Quercetin is a flavonoid commonly found in vegetables. It is thought to have anti-inflammatory properties by inhibiting mast cell activity and histamine release. Another study found that quercetin was similarly effective in children. Prolonged intake and high doses could cause stomach discomfort among other side effects.

Yamada S, Shirai M, Inaba Y, Takara T. Effects of repeated oral intake of a quercetin-containing supplement on allergic reaction: a randomized, placebo-controlled, double-blind parallel-group study. Eur Rev Med Pharmacol Sci. 2022 Jun;26(12):4331-4345. doi: 10.26355/eurrev_202206_29072. PMID: 35776034.

Marseglia G, Licari A, Leonardi S, Papale M, Zicari AM, Schiavi L, Ciprandi G; Italian Study Group on Pediatric Allergic Rhinoconjunctivitis. A polycentric, randomized, parallel-group, study on Lertal®, a multicomponent nutraceutical, as preventive treatment in children with allergic rhinoconjunctivitis: phase II. Ital J Pediatr. 2019 Jul 18;45(1):84. doi: 10.1186/s13052-019-0678-y. PMID: 31319883; PMCID: PMC6637471.