One thing that most people are unaware of is that there are so many health benefits that come along with OPC3 supplements. If you are unaware of what OPC3 is then you may want to continue reading this article to get a better idea. OPC is an antioxidant that is mainly found in supplements and is known as Oligomeric Proanthocyandins, and is also made up of bioflavonoid, and organic acids. One of the main things that OPC3 does for you is helps to maintain circulation in the body.