On-line Oligomeric Proanthocyanidins

Scientific Name: Pine Bark Extract

Other Names: French Marine Pine Bark Extract, French Maritime Pine Bark Extract, Leucoanthocyanidins, OPC, Oligomeric Proanthocyanidins, PCO, Pine Bark, Pinus maritima, Pinus pinaster, Procyandiol Oligomers, Procyanodolic Oligomers, Pycnogenol, Pygenol

Who is this for?

The most common use of pine bark extract is to prevent and treat a condition known as chronic venous insufficiency. Chronic venous insufficiency occurs when valves in the veins that carry blood back to the heart are weak or damaged and blood collects in the veins of the legs. This collection of blood can lead to varicose veins, spider veins, or sores on the legs. Results that are more serious can include blood clots in the legs. Bioflavonoids called proanthocyanidins in pine bark extract help keep veins and other blood vessels from leaking. Because it strengthens the walls of all blood vessels, pine bark extract may also be effective for slowing retinopathy, the gradual break down of the retina in the eyes. Individuals with arteriosclerosis (a build up of fatty deposits in the arteries), diabetes, or other conditions that increase the likelihood for damage to the small blood vessels in the eyes are more likely to have serious vision problems as a result of blood vessel damage.

Pine bark extract has antioxidant activity. Therefore, taking it helps to limit free radicals — chemicals that are produced during the breakdown of foods in the body and that can damage cells. Since exercise can produce free radicals, some athletes use pine bark extract to improve their exercise performance. Similarly, some men use pine bark extract because its antioxidant effects are thought to improve fertility by increasing sperm quality and movement. Because pine bark extract may increase the body's production of nitric oxide, a chemical involved in male sexual response, it may also be useful in treating erectile dysfunction.

Some evidence appears to show that pine bark extract could be helpful for other chronic conditions. In a small study of individuals with no medical problems, taking pine bark extract for 12 weeks resulted in lower blood pressure and thinner blood. In studies of animals with artificially-induced diabetes, injected pine bark extract produced significant reductions in blood sugar levels. Other studies have shown some effectiveness for pine bark extract in relieving pain for women with abdominal pain due to endometriosis. In laboratory and animal studies, pine bark extract may also have enhanced immune function. In other laboratory studies, pine bark extract appeared to prevent the accumulation of proteins similar to those associated with Alzheimer's disease. While clinical research continues for these conditions, no definitive results prove that pine bark extract is effective for any of them.

Oral pine bark extract may help to even out the tone of skin that has been darkened by various pigmentation disorders such as melasma. In China, a prescription product containing pine bark extract has been approved for treating skin pigmentation conditions. In the United States, pine bark extract is included in a number of face creams that claim to fight aging or restore wrinkled skin, but these claims are not documented by scientific research. Pine bark extract is also being investigated to determine if it can help prevent sunburn and skin damage from sun exposure.

When should I be careful taking it?

Individuals who have autoimmune conditions should not take pine bark extract due to its effects on the immune system. Some autoimmune conditions include:

  • Crohn's disease
  • Multiple Sclerosis
  • Psoriasis
  • Rheumatoid Arthritis
  • Systemic Lupus Erythematosus
  • Type 1 diabetes


Not enough is known about how pine bark extract affects a developing baby to recommend its use in pregnant women. Breast-feeding women should also avoid taking pine bark extract because it may pass to the baby in breast milk. No studies of pine bark extract have been conducted in children, so its potential effects in small children are unknown.

What side effects should I watch for?

Few side effects have been reported with the use of pine bark extract. The most frequently reported side effects have been mild gastrointestinal complaints such as nausea or upset stomach.

What interactions should I watch for?

Because it can enhance immune system function, pine bark extract may interfere with the effects of drugs used to suppress the immune system after organ transplants or in other conditions. Taking pine bark extract is not recommended for individuals who take drugs such as:

  • azathioprine (Imuran)
  • cyclosporine (Neoral, Sandimmune)
  • daclizumab (Zenapak)
  • mycophenolate (CellCept)
  • sirolimus (Rapamune)
  • tacrolimus (Prograf)

It is best not to take pine bark extract and corticosteroids at the same time. Corticosteroids are used for a variety of inflammatory conditions including arthritis, asthma, cancer, eye conditions, and skin infections. Commonly prescribed corticosteroids include:

  • beclomethasone (Beconase, Beclovent, Vancenase, Vanceril)
  • dexamethasone (Decadron)
  • hydrocortisone
  • methylprednisolone (Medrol)
  • prednisolone
  • prednisone (Deltasone, Orasone)
  • triamcinolone (Azmacort, Nasacort)

No interactions have been reported between pine bark extract and non-prescription drugs, other herbal supplements, or foods. However, despite a number of studies that have been conducted in humans, its possible interactions with drugs, foods, and other dietary supplements are not understood completely. Be sure that your doctor and pharmacist are aware of all the prescription and non-prescription medicines you take before you begin to use pine bark extract or any other herbal supplement.

Some interactions between herbal products and medications can be more severe than others. The best way for you to avoid harmful interactions is to tell your doctor and/or pharmacist what medications you are currently taking, including any over-the-counter products, vitamins, and herbals.

Should I take it?

Pine bark extract is obtained from the inner bark of a specific type of pine trees that grow mainly in the coastal areas of southwestern France. Since the 1850s, forests of these trees have been planted for use as lumber and paper. Through careful planting and harvesting, the forests now cover more than 2 1/2 million acres. As trees are cut, their fresh bark is removed, the inner layer is separated from the rough, outer bark, and the inner bark is then processed to produce powdered bark for oral or topical products.

Pine bark extract contains chemicals that have various effects. Some of them act as antioxidants in the body. Antioxidants are thought to protect body cells from damage caused by a chemical process called oxidation. Pine bark extract also has anti-inflammatory effects. Inflammation is often a response to irritation, injury, or infection and it usually includes pain, redness, and swelling in the area of the damage. Inflammation can occur within body tissues as well as on the surface of the skin.

Dosage and Administration

Pine bark extract is commonly used in Europe and Asia. Standardized commercial preparations were introduced to the U.S. market in the late 1980s. Standardization by the manufacturer should assure the same amount of active ingredient in every batch of the commercial preparation. Generally, pine bark extract capsules, tablets, or oral liquid forms should contain between 85% and 90% of proanthocyanidins (also known as polyphenols), the active ingredient of pine bark extract. Lotions or creams usually contain between 0.5% and 2% of pine bark extract.

Dosing varies, but typical doses used in clinical studies include:

For chronic venous insufficiency: 45 mg to 360 mg per day — usually divided into three doses.
For retinopathy: 50 mg three times a day
For uneven skin tone: 1 mg to 1.7 mg per kilogram of body weight per day (a kilogram is about 2 1/4 pounds)
For exercise enhancement: 200 mg three times a day
For male infertility caused by low sperm count: 200 mg once a day
For coronary heart disease: 150 mg three times a day
For high cholesterol: 120 mg three times a day
For abdominal pain in women: 30 mg to 60 mg once a day


Pine bark extract has been shown in studies to help relieve the swelling and pain associated with chronic venous insufficiency in the legs and to delay or prevent damage to blood vessels in the retinas of the eyes. Study evidence also supports its use in enhancing exercise capacity, improving fertility for men with inadequate sperm quality and/or movement, and smoothing out uneven skin color.

Less evidence is available for a number of other proposed uses for pine bark extract such as relieving symptoms of coronary artery disease, lowering cholesterol, lessening abdominal pain from endometriosis, and treating Alzheimer's disease. Further research is needed before these and other possible uses of pine bark extract can be recommended.


Due to its enhancement effects on the immune system, pine bark extract should not be taken by transplant recipients or by individuals who have autoimmune conditions. Because little is known about pine bark extract, its use is also not recommended for children, pregnant women, or women who are breast-feeding.

Side Effects

Other than nausea, few side effects have been attributed to the use of pine bark extract, but not enough information about it is available to determine whether or not other side effects are possible.


The immune system effects of pine bark extract make using it inappropriate while taking immunosuppressive drugs or corticosteroids.


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(Note: The above information is not intended to replace the advice of your physician, pharmacist, or other healthcare professional. It is not meant to indicate that the use of the product is safe, appropriate, or effective for you.)

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