Oligomeric Proanthocyanidin (OPC) is a type of flavonoid found in various plants, particularly in the bark of the pine tree, the seeds of grapes, and the skins of fruits like apples and berries. These compounds are known for their antioxidant properties, which help protect cells from damage caused by free radicals. OPCs are often studied for their potential health benefits, including supporting cardiovascular health and improving circulation. They may also have anti-inflammatory effects and contribute to skin health. Due to these properties, OPCs are commonly included in dietary supplements and health products.