Proanthocyanidins are a class of flavonoids found in various plants, particularly in the bark of trees, fruits, and seeds. They are known for their antioxidant properties, which help protect cells from damage caused by free radicals. Common sources include grapes, cocoa, and berries. These compounds may offer several health benefits, such as improving cardiovascular health and supporting skin health. Research suggests that proanthocyanidins can enhance blood circulation and reduce inflammation, making them a topic of interest in nutritional studies and natural health products.