When reading product labels, magazine articles and many popular books, these terms should be considered as generic words and not scientific. In most cases, the terms are used interchangeably for commercial interests—or by mistake—and their differences have truly lost their scientific meanings.

Only in the academic science literature does each term have a distinctly different meaning, as reviewed below:

Anthocyaninins or Anthocyanidins
Bioflavonoids
Flavanols or Bioflavanols
Flavonoids
Leucocyandiols or Leucocyanidins or Leucoanthocyanins
Oligomeric Proanthocyanidins or Proanthocyanidolic Oligomers
OPC or OPCs or PCO or PCOs
Proanthocyanidins or Proanthocyanins
Procyanidines or Procyanidols
Procyanidins
Polyphenols

POLYPHENOLS: a very broad class of substances that are structurally related. There is always a phenolic acid group attached to one of the benzene rings in bioflavonoids, therefore all bioflavonoids are also referred to as "polyphenols" or "phenols." ("Poly" is from the Greek root which refers to "more than one" or "many" phenols.) All of the compounds below are in the polyphenol class because they are structurally related (and may or may not be pigmented).

BIOFLAVONOIDS: the subgroup of flavonoids that possess biological activity ("bio" is a Greek prefix that indicates a relationship to life). In some cases the differences between certain bioflavonoid members outnumber the similarities: some bioflavonoids are toxic, others are innocuous, some are inefficacious, others are useless, some are bioavailable, others are not. NOTE: Much of the contemporary scientific literature, and this web site, omits the "bio" prefix and simply refers to bioflavonoids as flavonoids.

FLAVONOIDS: a very broad class of compounds that are defined by color (pigment). The term is derived from the Latin word "flavus," which means yellow. For originally, and chemically speaking correctly so, flavonoid was the name for yellow plant pigments, like lemons, oranges and grapefruits. All of the compounds below are in the flavonoid class, as they are related by their pigment.

FLAVANOLS or BIOFLAVANOLS: the group of compositions built from one molecule, "flavan-3-ol." This molecule distinguishes itself by its natural tendency towards condensation--towards forming stable compositions of two, three, four or more flavan-3-ol molecules bonded to each other. This is how the flavan-3-ol naturally comes in singles (catechins or monomers), organic clusters of dimers (2), trimers (3), tetramers (4) and pentamers (5), also known as oligomeric proanthocyanidins (oligo=few), and so on (clusters larger than pentamers are known as tannins, or polymeric proanthocyanidins). The distinguishing feature of flavanols is that all members of this group are made up of only one molecule: the flavan-3-ol. Dr. Jack Masquelier argues that flavanols should not be regarded as a subclass of the flavonoids because the nucleus of the flavanol differs biochemically and pharamcologically from flavonoids—the flavanol differs so much from flavonoids that the molecules are not similar in behavior.

LEUCOCYANDIOLS or LEUCOCYANIDINS or LEUOCOANTHOYCYANINS: older names (circa 1940s-1970s) used to describe flavanols.

ANTHOCYANINS or ANTHOCYANIDINS: the polyphenols that have red pigments. Anthocyanins are highly fragile and not interesting from a medical point of view or for their capillary resistance unless they exist in an acidic environment, such as in red wine.

PROANTHOCYANIDINS or PROANTHOCYANINS: colorless polyphenols that are referred to as proanthocyanidins because the coloration towards red is their major trait of authentication from a chemical point of view. For example, when leaves naturally change from green to red in the fall, they transform colorless proanthocyanidins into colorful anthocyanidins. They exist before or pro the anthocyanidins (the term "before" is synonymous with "pro" in Latin); hence the name, proanthocyanidins.

PROCYANIDINS: a contempoary term for proanthocyanidins.

PROCYANIDINES or PROCYANIDOLS: French names for proanthocyanidins.

OLIGOMERIC PROANTHOCYANIDINS or PROANTHOCYANIDOLIC OLIGOMERS: naturally-occurring group of pairs and triples of the single molecule, "flavan-3-ol," which is found in most plants. ("Oligo" is Greek for "few," as opposed to "mono," the Greek word for "one" or "single.")

OPC or OPCs or PCO or PCOs: short names for oligomeric proanthocyanidins or proanthocyanidolic oligomers. MORE...

FLAVAY® : the precisely defined flavanol complex that primarily consists of catechins, dimers and trimers that are naturally-derived from plant sources; patented and perfected by the inventor, Dr. Jack Masquelier, validated by the French Ministry of Health and documented by a library of research consisting of many patents and hundreds of scientific papers, articles, doctorate theses, lectures and presentations.

Consumers should be aware that some manufacturers of grape seed extracts have devised ways to artificially boost the proanthocyanidins in their extracts in the test tube. However, there is no scientific research to show whether the human body benefits from this artificial method. Our products, FLAVAY® and FLAVAY PLUS® use ONLY the original manufacturing process developed and patented by Dr. Jack Masquelier in France, which captures the NATURALLY-DERIVED oligomeric proanthocyanidins in plants.

Consumers also need to know that the marketplace is full of imitations, various “extracts” and derivative forms of Dr. Masquelier’s scientifically proven and patented complex. Unfortunately, many have even used Dr. Masquelier’s name and research in unauthorized ways to promote illegitimate products.

FLAVAY® is the name you can trust for the precisely defined active polyphenol complex patented and perfected by the inventor, Dr. Jack Masquelier, validated by the French Ministry of Health and documented by a library of research consisting of many patents and hundreds of scientific papers, articles, doctorate theses, lectures and presentations. For quality, consistency, bioavailablity and safety, consumers may rely upon FLAVAY® .