What is grape seed extract grape seed extract is derived from the small seeds and sometimes the skins of red grapes they are actually the same grapes pressed to make wine grape seed extract is high in the flavonoids oligomeric proanthocyanidins opc it has been shown to remain in the body for as long as 72 hours and is also 20 times stronger than vitamin c and 50 times more potent than vitamin e grape seed extract benefits grape seed extract is standardised to 95 oligomeric proanth