Source Naturals OPC-85 is a potent natural antioxidant derived from the bark of the European coastal pine, Pinus maritima. It is the original product of Dr. Jacques Masquelier, the researcher who first isolated and identified oligomeric proanthocyanidins, or OPC's. OPC's are powerful plant compounds which have been shown to have exceptional free-radical scavenging activity, and which help preserve the integrity of body tissues. They belong to a larger class of compounds called bioflavanols, a group of substances which are built out of the same molecule - the flavan-3-ol molecule. Source Naturals OPC-85 is guaranteed to contain 85% bioflavanoids for maximum benefit.