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Pine Bark Extract

Other common name(s): Flavangenol, Oligopin, pine bark extract, Prelox, pygenol, Pycnogenol, Masquelier's Original OPCs (oligomeric proanthocyanidins)

Scientific/medical name(s): Pinus pinaster


Pine bark extract is made from the bark of the maritime pine tree (Pinus pinaster), which contains naturally occurring chemicals called proanthocyanidins. The maritime pine is native to the western Mediterranean, with a range extending over Portugal, Spain, France, Italy, and Morocco. Pine bark extract has been commonly sold under the brand name Pycnogenol, although there are a growing number of new ones.

Pycnogenol is also the name of a group of compounds that contain proanthocyanidins taken from a number of natural sources, such as grape seeds (see Grapes) and other plants. In addition to the Pycnogenol brand, there are several other pine bark extract supplements available, which may use different types of pine bark and have different formulations. Pine bark extract is often used for its antioxidant properties.


Although there is interest in pine bark extract among medical researchers, only limited data from clinical trials supports the claims made about its benefits for health. A few early studies in humans have shown possible benefits in reducing swelling from a circulation disorder called chronic venous insufficiency, but this needs further research. Laboratory studies have indicated pine bark extract may have some antioxidant properties.

How is it promoted for use?

Proponents claim that pine bark extract is a powerful antioxidant. Antioxidants are compounds that block the action of free radicals, activated oxygen molecules that can damage cells. Supporters believe pine bark extract protects against arthritis, allergies complications from diabetes, cancer, heart disease, and problems with circulation such as swelling and varicose veins. Other reported benefits include improved memory, fewer effects from stress, better joint flexibility, lower blood pressure, and decreased inflammation. More recently it’s been touted as a treatment for psoriasis and as “herbal Viagra” in formulas for men and women. Some claim that pine bark extract supplements are much more effective in eliminating free radicals than vitamins C and E.

What does it involve?

Pine bark extract is available as a tablet and capsule in a range of strengths. Practitioners may recommend a dose ranging from 25 milligrams (mg) to 300 mg per day for up to 3 weeks. After that, some suggest a maintenance dose of 50 to 100 mg per day, while others recommend continuing a “saturation dose” of 20 to 30 mg per 20 pounds of body weight. Others recommend doses of 600 mg or more per day, depending on the reason for taking it.

What is the history behind it?

In the winter of 1535, a French explorer named Jacques Cartier found his ship ice-bound in the St. Lawrence River, in what is now Quebec. Having no fruits or vegetables, the crew became ill with scurvy, a disease resulting from vitamin C deficiency. Several had already died when a Native American showed them how to prepare a tea made from tree bark. Many crew members recovered and attributed miraculous qualities to the tea. It is thought now that the tea was prepared from the bark of the Eastern White Cedar tree and that it contained large amounts of vitamin C.

In 1951, French researcher Dr. Jacques Masquelier reportedly read this account in Cartier’s writings and began a search for the active ingredients in the tea. He was able to extract proanthocyanidins from the bark of the European coastal pine tree. He patented the process and named the compound Pycnogenol.

In 1970, proanthocyanidins were also extracted from grape seeds. The compound found in grape seeds and plants is referred to as either proanthocyanidins or pycnogenol. However, it differs somewhat from the pycnogenol extracted by Dr. Masquelier.

More recently, others have patented different pine bark extracts, some in combination with other substances, to sell under different names.

What is the evidence?

There are not enough data from clinical trials to support most of the health claims made for any form of pine bark extract, although interest in proanthocyanidins among medical researchers is growing. There are reports from small studies in humans that pine bark extract may be helpful in treating circulation disorders. One clinical trial began in August 2003 to find out if pycnogenol can help reduce lymphedema (swelling from fluid buildup, which can occur after procedures in which lymph nodes are affected) after treatment for breast cancer. This study was completed but no results can be found in the available medical literature. A second clinical trial that was set up in a similar way also didn’t publish reports of its findings.

A small study found that a single high dose of pine bark extract in the form of a bioflavonoid mixture was effective in reducing platelet clumping in smokers for more than 3 days, which would be expected to reduce blood clotting. An Italian study suggested that pycnogenol might also reduce blood clotting during long airplane flights. These studies may mean that pine bark extract could lower risk for stroke or heart attack, but clinical studies to find out whether this is true have not been done.

Some small brief studies have been done to look at pine bark extract’s possible usefulness in treating asthma, menstrual pain, blood clots and leg swelling during long airplane flights, retinal disease in diabetics, high cholesterol, and other disorders. All of these studies need to be done on larger groups of people under carefully controlled conditions to find out whether pine bark extract actually helps any of these problems. A 2012 study tried to overcome this problem by pooling similar studies of the effects of pine bark extract on a number of chronic diseases. Looking at the studies of each disease together, the researchers still couldn’t find enough evidence to reach any conclusions about pine bark extract in the treatment of diabetes, asthma, chronic venous insufficiency, erectile dysfunction, high blood pressure, and osteoarthritis.

A 2014 study looked at all the previous studies on the effect of pine bark extract on cholesterol and other fats in the blood that are known risk factors for heart disease. While it did find some effect on “bad” cholesterol at higher doses, there was no other link between any other blood fats. The study concluded that pine bark extract didn’t have a significant effect on them.

Studies also suggest pine bark extract has antioxidant properties, which are sometimes helpful in reducing cancer risk. Further research is needed to find out whether pine bark extract may have any benefit for preventing or treating cancer.

Are there any possible problems or complications?

This product is sold as a dietary supplement in the United States. Unlike companies that produce drugs (which must be tested before being sold), the companies that make supplements are not required to prove to the Food and Drug Administration that their supplements are safe or effective, as long as they don't claim the supplements can prevent, treat, or cure any specific disease.

Some such products may not contain the amount of the herb or substance that is on the label, and some may include other substances (contaminants). In a 2013 study, a test of 44 samples found that fewer than half the herbal supplements tested contained any of the herb that was listed on the label. More than half the samples contained ingredients that were not on the label. This suggests that the 2007 FDA rules to assure the proper listing of supplement ingredients are not always followed. Even when they are, the rules do not address the safety of the ingredients or their effects on health.

Most such supplements have not been tested to find out if they interact with medicines, foods, or other herbs and supplements, or if they even contain the ingredients on their labels. Although some reports of interactions and harmful effects may be published, full studies of interactions and effects are not often available. Because of these limitations, any information on ill effects and interactions below should be considered incomplete.

A few supplement makers pay the US Pharmacopeia to test and verify that their products contain the ingredients listed on their labels. These supplements all have the USP Dietary Supplement Verified mark on their labels.

Pine bark extract has been reported to be safe. Some people report mild problems such as headache, nausea, dizziness, and upset stomach. Not much is known about possible interactions with other drugs and herbs. Because it is an antioxidant, it may interfere with the action of cancer treatment drugs. Because it might interfere with blood clotting, it might increase the risk of bleeding in people taking blood thinners (anticoagulant drugs). Always tell your doctor and pharmacist about any herbs or supplements you are taking.

Allergic reactions to pine are possible, although reactions to pine bark extract have not been reported in the available medical literature. Pine bark extract has not been studied in pregnant or breast-feeding women.

Relying on this type of treatment alone and avoiding or delaying conventional medical care for cancer may have serious health consequences.

To learn more

More information from your American Cancer Society

The following information on complementary and alternative therapies may also be helpful to you. These materials may be found on our website (www.cancer.org) or ordered from our toll-free number (1-800-ACS-2345).

Dietary Supplements: What Is Safe?

The ACS Operational Statement on Complementary and Alternative Methods of Cancer Management

Complementary and Alternative Methods and Cancer

Placebo Effect

Learning About New Ways to Treat Cancer

Learning About New Ways to Prevent Cancer



Araghi-Niknam M, Hosseini S, Larson D, Rohdewald P, Watson RR. Pine bark extract reduces platelet aggregation. Integr Med. 2000;2:73-77.

Belcaro G, Cesarone MR, Rohdewald P, et al. Prevention of venous thrombosis and thrombophlebitis in long-haul flights with pycnogenol. Clin Appl Thromb Hemost. 2004 Oct;10(4):373-377.

Cesarone MR, Belcaro G, Rohdewald P, et al. Prevention of edema in long flights with Pycnogenol. Clin Appl Thromb Hemost. 2005;11:289-294.

Devaraj S, Vega-López S, Kaul N, et al. Supplementation with a pine bark extract rich in polyphenols increase plasma antioxidant capacity and alters the plasma lipoprotein profile. Lipids. 2002;37:931-934.

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Memorial Sloan Kettering. Pine Bark Extract, August 12, 2013. Accessed at www.mskcc.org/cancer-care/herb/pine-bark-extract on May 7, 2014.

National Toxicology Program. Summary of data for chemical selection: oligomeric proanthocyanidins from grape seeds and pine bark. Accessed at http://ntp.niehs.nih.gov/ntp/htdocs/chem_background/exsumpdf/grapeseeds_pinebark_508.pdf on May 7, 2014.

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Petrassi C, Mastromarino A, Spartera C. PYCNOGENOL in chronic venous insufficiency. Phytomedicine. 2000;7:383-388.

Pütter M, Grotemeyer KH, Würthwein G, et al. Inhibition of smoking-induced platelet aggregation by aspirin and pycnogenol. Thromb Res. 1999;95:155-161.

Pycnogenol for the treatment of lymphedema. Clinical Trials Web site. Accessed at www.clinicaltrials.gov/ct/show/NCT00214032 on June 6, 2008.

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US Pharmacopeial Convention. USP Verified Dietary Supplements. Accessed at http://www.usp.org/usp-verification-services/usp-verified-dietary-supplements on January 5, 2015.

Note: This information may not cover all possible claims, uses, actions, precautions, side effects or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for consultation with your doctor, who is familiar with your medical situation.

Last Medical Review: 06/04/2014
Last Revised: 01/15/2015