Natural FactorsBioactive Quercetin EMIQ 50 mg with Vitamin C, Supports Sinus, Heart and Immune Health, 60 Capsules

What is the bioavailability percentage of this emiq quercetin?

Question for the seller: which country do you source your raw material for quercetin? not where it is manufatured please specify country

How much quercetin per capsule ... 50mg is listed, but 50mg of what? ingredients list 167mg emiq ... but that's more than quercetin, right?

Is this derived from corn, citrus, or legumes?