© 2017 by OPC-DOC

OPC, these are oligomer procyanidins or proanthocyanidins. They are a part of the group of flavanols, but not to the group of flavanoids, which they are sometimes mistakenly categorized in. The barks of the stone pine or the red grapes contain a high amount of proanthocyanidins, for example catechin, epicatechin, ECGallate, taxifolin and TFGlucoside.

These substances are so-called monomers, which means that they usually appear as single molecules. Catechins appear in green tea and explain its positive healthy effect. But as long as these molecules stay on their own (monomer proanthocyanidins) their effect is low. Only if they connect to multi-chain (= oligomer) molecules, the healing features appear. Proanthocyanidins become oligomer proanthocyanidins (OPC).

But there's also a requirement for the effect of the OPCs: The chains can only consist of a maximum of 5 molecules (pentamers).  With 6 molecules, the OPCs can no longer enter the cell walls, because the chain is too big. This way, the OPCs cannot take effect. Only dimer (two-parted-chains) up to pentamers, the maximum, have a high bioavailability, which means they take effect in the body. The most effective OPC extracts are the ones with a high amount of short-chained OPCs. Ideally dimers and trimers. The amount should be about 30%.

Historic Development


In the 40s they were discovered by the Frenchman Masquelier when he analyzed the ingredients of the red inner skins of peanuts for poisonous components. Thereby he found a fabulous substance with a strong protective effect for blood vessels, the OPC.


This was introduced on the market in 1950 under the name of ResivitTM. Shortly after that, when the peanut skins were not available anymore in sufficient quantities due to economic developments, another virgin material needed to be found. They found plenty of it in the bark of pinus maritima, a kind of pine tree that can be found in the Bordeaux area. Masquelier developed a procedure where the obtained extraction amount of OPC and catechins was between 85 and 90 percent. Further substances, such as tannins and catechins are contained equally in low amounts, which supports the effect of the OPC. This flavanol mixture was released on the market under the name FlavanTM.


In 1955 Masquelier was able to provide evidence that the same oligomeric procyanidins can also be found in the cores and skins of grapes and that the flavanols, for example the rutin (that is not bioavailable according to Masquelier) are superior to the flavanoids in respect of their blood vessel protecting effect. In contrast, OPC has almost a 100% bioavailability. This is how the third vessel protection agent, based on grape seeds, was introduced to the market in France under the name Endotélon TM.


Within minutes it is being absorbed via the oral and gastric mucosa into the blood and spreads in a relatively short amount of time in all the different organs, as well as in the entire body tissue right up to the skin, hair and nails. It is absolutely nontoxic and is mostly being utilized by the body. OPC is water-soluble, reaches its highest concentration in the blood within 45 minutes and is fully used up within 72 hours. It passes the blood-cerebral barrier just like vitamin C and also takes full effect in the brain. Already 24 hours later, the resilience of the blood vessels doubled.



In all so far executed studies, no side effects were found. Studies of the Pasteur Institute and the Huntington Institute revealed that OPC is nontoxic, not carcinogenic (cancer-causing) and not mutagenic (change of genetics). In comparison to the flavanoids, OPC connects with protein, especially with collagen. Anne Somin reports of fragile and porous capillaries as a result of an OPC shortage with all associated sequelae in "The OPC Health Book" (published in 1998 in the Scherz publishing company) and says there's a twentyfold higher antioxidant effect with sufficient intake, than with vitamin C and the 40 - 50-fold effect potential of vitamin E, as well as the lowering of a too high cholesterol level. Furthermore, OPC strengthens blood vessels and thereby prevents cardiac and circulatory diseases, because, unlike vitamin C, it connects with protein, especially collagen and elastin and doubles the resilience of the blood vessels within only 24 hours. In addition the following things are named as a consequence of adding OPC: Higher blood circulation, stronger resilience, improvement of the memory, lowering of the aging process, prevention of carious and arthritic inflammations, as well as strengthening of the immune system.

In studies with guinea pigs in 1976, Masquelier and colleagues could prove that OPC extremely improves the effect of vitamin C, which in return additionally improves the effect of the OPC, so that we deal here with a strong synergistic effect (the collaboration of different substances in additive or potentiating effect).


For this research, the guinea pigs were separated into different groups and provided with staggered vitamin C and OPC. The more vitamin C the animals got, the stronger they were and the longer they lived. The most interesting result, however, was that the guinea pigs (guinea pigs can also not produce vitamin C themselves and are one of the few exceptions in the animal kingdom) that got the Lowest amount of vitamin C (5 mg per kilo body weight daily), also got 20mg OPC

per kilo of their bodyweight everyday

and were in the same health condition as the animals, that received 20 mg of vitamin

daily. So OPC can be seen as a synergistic vitamin C and survival is granted with OPC

even if vitamin C is not provided in sufficient amounts.


There are a lot of arguments for seeing OPC as vitamin P. Prof. Dr. Jack Masquelier

said on the 18th of October 1996 on a scientific presentation in Baltimore:

"One could say that with my publication of this comprehensive table

proanthocyanidins, OPC, can be seen as "collagen vitamins", because they are

part of the biosynthesis of collagen and prevent damage.

Let's first of all take a look at the biosynthesis. As you know, the biosynthesis of collagen needs ascorbic acid, vitamin C, because the amino acids proline and lysin need to be hydroxylated before they can be incorporated as a physiological active collagen. The OPC behaves just like the cofactor of vitamin C, enhances its effect and therefore activates the collagen production."


Valuable proanthocyanidins can be found in the dyestuffs of many plants and foods