Consumers need to realize that there is no set scientific standard for accurately identifying and quantifying products sold as OPC. The result is that most "OPC" products contain unidentified and untraceable extracts typically labeled vaguely as "grape seed extract".

Some "OPC" products contain nothing more than grape seeds or other plant parts which have been pulverized in a food processor --because producing extracts is infinitely less costly than isolating OPCs.

The manufacturers that do isolate proanthocyanidins then fail to remove the many large "polymeric" proanthocyanidins (PPC) from among the small "oligomeric" proanthocyanidins (OPC).

The complex structure of Proanthocyanidins

Unlike single nutrients such as vitamin C (ascorbic acid) and vitamin E (d-alpha-tocopherol), proanthocyanidins are very complex and require specialized knowledge and technology in order to be accurately identified and quantified.

Proanthocyanidin comes in two forms:

1. Polymeric proanthocyanidin (PPC) or tannins - These are large molecules and are unabsorbable in the intestines hence becomes waste and are dangerous in large amounts.
2. Oligomeric proanthocyanidin (OPC) - these are short chain molecules, readily absorbable and considered to be the most powerful antioxidant.

Study the structures below.

OPCs are made up of catechin (monomer) and epicatechin (monomer) molecules joined in a chain. When two monomers are joined to form a chain, we call it a dimer, 3-trimer, 4-tetramer, 5-pentamers. OPC should be strictly 5 monomers only. 6 monomers and above is considered a PPC. Single catechins and single epicatechins act differently from those that are bonded as OPCs. Oligo means few. Poly refers to many or much. Certain producers of grape seed oil extract has no method to separate OPC and PPC from their extracts or they simply mix PPC & OPC to increase weight. Never be fooled by appearances! Buy from only what is proven and tested!

The difference between OPC & PPC

Only buy from a reputable company who ensures that you are getting high quality grape seed oil extract.