Grape Seed OPC is extracted from red grape seeds, which have a high content of compounds known as oligomeric proanthocyanidins (OPCs). OPC possesses potent antioxidant properties and is chemically known as flavonoids or polyphenols.

Original support for Grape Seed OPCs came from the “French Paradox”. This health phenomenon attributes to the low incidence of heart disease in France, despite the high fat intake, to large consumption of red wine. The cardioprotective effects of red wine and red grape juice is derived from a group of compounds called flavonoids, catechins, tannins, and proanthocyanidins, which are found at high concentrations in red grapes. These compounds are found at especially high levels in the seeds of the grape, where they can be extracted and concentrated for use as a dietary supplement. Research on the chemical properties of grape seed extract has shown them to be powerful antioxidants that are even more potent than the more commonly used antioxidants such as vitamins C and E.