Jarrow Formulas - Hawthorn 500 mg. - 100 Capsules Hawthorn (Crataegus oxyacantha) has been used for centuries to aid circulation. Clinical research has identified the beneficial compounds responsible for hawthorn s activity. These compounds include flavonoids, such as vitexin 4 -rhamnoside, O-glycosides, luteolin-7 glucoside, hyperoside, quercetin and rutin. Hawthorn contains a powerful antioxidant that protects cells of the cardiovascular system from free radicals. Hawthorn promotes efficient heart function.