Yes but unfortunately too many, and most with misleading claims or dubious recommendations due to high doses being potentially problematic. Flavonoids occur in plants and help ward off plant diseases. More than 4000 flavanoids have been identified and found in our fruits, beverages (coffee, tea, beer, wine, etc.) and vegetables. Interest has grown regarding their potential benefits in human health such as effects on cardiovascular disease and cancer. But it’s far from certain on amounts and what types are needed. Additionally unusual levels of flavonoids can interfere with the activity of many of our body’s enzyme systems and hormone metabolism - mainly estrogen and thyroid hormones. Therefore we have no recommendation for a flavonoid supplement at this time.
But do eat your fruits and vegetables that contain flavanoids because you could never get too much from simply eating. As an example, people in the United States, Europe and Asia get ~5-70 milligrams of quercetin (the most widely sold flavone) from daily diet, but a common health food supplement recommends taking 1,000 milligrams in one pill, which is 10 to 20 times more than even a high dietary intake of quercetin. So eat your fruits and vegetables to get your proper flavonoid intake and take a good multivitamin and mineral formula for anything that you might miss from your daily diet.