... body. Many names refer to this set of bioflavonoids, including OPC's, Oligomeric Procyanidolic Complexes, leuco anthocyanin, anthocyanidin and also others ... . Most of us take it as OPC's, which are types of bioflavonoids, very powerful ones. ... It was this very ability that led to their discovery. OPC bioflavonoids have the uncanny ability to strengthen blood vessel walls ...