NutriJa Quercetin each serving provides 100mg of the highest quality quercetin supplement ethically sourced, grown and cultivated using an extraction process to ensure 95% standardized purity. NutriJa Quercetin capsules contain Sophora Japonica which is derived from from Japanese Cord Tree Flower Extract and are naturally present in fruit, vegetables and herbs. benefits important for the management of occasional seasonal discomfort. And it supports immune system.