OPC-100™ (Leucoselect® Phytosome)

Thorne Research

Price: OPC-100™ (Leucoselect® Phytosome)
Size: 60 capsules

Proanthocyanidins are antioxidants that are widespread in nature. Their modern use as antioxidants dates to the maritime pine tree bark (Pinnus maritima). More recently, they have also been produced from an extract from grape seeds ("grape seed extract"). They are excellent antioxidants, at least 20 times more potent than Vitamin C in some situations.

The world first learned of their beneficial effects when a Frenchman, Jacques Cartier, led a party of explorers into what is now the St. Lawrence gulf in Canada, in 1535. The explorers were very sick at the time, suffering from symptoms of scurvy. Native Americans told them that they should drink a tea made from the Anneda tree (a relative of the Prunus maritima tree). This recommendation returned the explorers to vigorous health.

Proanthocyanidins can be called a bioflavonoid (the yellow-colored substances from plants). Bioflavonoids enhance absorption of Vitamin C, and are also both powerful antioxidants and free radical scavengers. Some beneficial effects of bioflavonoids include strengthening capillaries and regulating their permeability. This may be why they help with retinal degeneration. They also help with ulcers, probably due to the same mechanism, and are effective with some cases of asthma. They have been documented to help with diseases such as bacterial infections, cancer, hypertension, viral infections, arthritis, diabetes, and many other disorders. Their antibacterial effect may be due entirely to their ability to strengthen cell wall membranes, and not by any direct antibacterial properties.

Proanthocyanidins will pass the blood-brain barrier and nurture dysfunctional neurons. Some people now believe that the Proanthocyanidins from pine bark (Pycnogenol) are actually superior, and are more potent that from grape seeds. The research behind this recommendation comes mostly from French researchers, especially Professor Masquelier, who published studies from 1983-1993. These studies showed both sources to be effective, but that the Proanthocyanidins from grape seed were more bioavailable that from pine bark and better free radical scavengers. The OPC's from grape seeds are far less expensive than pine bark sources, which makes them more cost effective.

We offer both products to allow you to choose the one you prefer. No matter what source one employs to produce Proanthocyanidins, the caretaker needs to be aware that these are complex phytochemicals having a large number of different compounds in each of the various products. It is likely that certain disorders would respond better to one source of Proanthocyanidins, while a different disorder might respond to a different one.

    Oligomeric proanthocyanidins (OPCs) are comprised of two, three, or more flavonoid molecules attached to each other. OPCs have strong free-radical scavenging (antioxidant) ability, resulting in inhibition of oxidative damage and protection of blood vessels and other tissues.

    OPCs have been shown to protect vascular endothelial cells from oxidative damage and appear to strengthen the resistance of cell membranes to injury and degradation. They also bind copper and iron, thereby reducing their oxidative effects.

    A clinical study of 10 healthy volunteers examining the effect of OPC supplementation on markers of oxidative stress showed significantly increased levels of alpha-tocopherol in red blood cell membranes. The primary ingredient in O.P.C.-100, Leucoselect Phytosome, markedly elevates blood total antioxidant capacity.

    In a randomized human trial, young healthy volunteers received Leucoselect Phytosome (containing 300 mg of Leucoselect daily) or a placebo. The blood Total Radical-trapping Antioxidant Parameter (TRAP, a measure of antioxidant activity) was measured at several time-points during day one and day five. Within 30 minutes after administration on day one, blood TRAP levels were significantly elevated compared to placebo.

    Other studies on Leucoselect Phytosome supplementation have demonstrated a reduction in the oxidation of LDL cholesterol in heavy smokers, reduced oxidative stress in diabetics, and a reduction in oxidative stress after a fatty meal.

    Evidence suggests OPCs stabilize collagen cross-linkage within skin and other connective tissues.

    OPCs have also been shown to decrease capillary permeability (thus decreasing bruising). Clinical studies demonstrate reduced swelling and improved resolution of sports injuries in athletes given OPCs prior to a sporting event.

    We might recommend OPCs for:

    • Retinal/Eye Disease
    • Vertigo
    • Idiopathic Vestibular disease
    • Head tilt Brain Disorders
    • Epilepsy Diabetes
    • Cancer
    • Certain geriatric conditions
    • General Antioxidant support


    • 1/4 capsule for each 10 lbs body weight, twice daily


    • 1/4 capsule 1-2 times daily, ok in foods


    • 1/32 capsule daily per bird
    • 1 capsule in 1 cup soft foods. Give each bird approximately 1/32 of a cup of soft food.

    One Capsule Contains:

    Grape Seed Phytosome (Vitis vinifera extract / Phosphatidylcholine complex) 100 mg.

    Other Ingredients:

    Microcrystalline Cellulose, Hypromellose (derived from cellulose) capsule, Leucine, Silicon Dioxide. This product uses Indena S.p.A.'s grape seed phytosome (Leucoselect). Leucoselect is a registered trademark of Indena S.p.A. Contains ingredient derived from soy (phytosome).