Penn Herb Wellness Guide
ProanthocyanidinsFind Products
Proanthocyanidins—also called "OPCs" for oligomeric procyanidins or "PCOs" for procyanidolic oligomers—are a class of nutrients belonging to the flavonoid family.
- Reliable and relatively consistent scientific data showing a substantial health benefit.
- Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
- For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement,little scientific support.
Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.
For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
This supplement has been used in connection with the following health conditions:
| Used for | Amount | Why |
|---|---|---|
Chronic Venous Insufficiency | 50 to 100 mg two to three times daily |  [3 stars] Proanthocyanidins, a group of flavonoids, have been shown to strengthen capillaries in double-blind research. |
Hypertension | 100–400 mg per day | as Grape Seed Extract[3 stars] Grape seed extract may lower blood pressure in people with pre-hypertension and mild hypertension, especially in those with other metabolic disturbances. |
Capillary Fragility | 150 mg daily |  [2 stars] Proanthocyanidins, flavonoids extracted from grape seeds, have been shown to increase capillary strength in people with hypertension and diabetes. |
Retinopathy | 150 mg daily | [2 stars] Proanthocyanidins, a group of flavonoids found in pine bark, grape seed, and other plant sources, may help slow the progression of diabetic retinopathy. |
Sunburn | 1.1 to 1.66 mg per 2.2 lbs (1 kg) of body weight per day during periods of high sun exposure | [2 stars] Proanthocyanidins are a group of flavonoids found in pine bark, grape seed, and other plant sources that may increase the amount of ultraviolet rays necessary to cause sunburn. |
Pancreatic Insufficiency | Refer to label instructions | as Grape Seed Extract [1 star] In a preliminary report, three patients with chronic pancreatitis who were treated with grape seed extract saw reduced frequency and intensity of abdominal pain. |
Varicose Veins | Refer to label instructions | [1 star] One trial found that supplementing with proanthocyanidins improved the function of leg veins in people with widespread varicose veins. |
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The information presented by TraceGains is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. Self-treatment is not recommended for life-threatening conditions that require medical treatment under a doctor's care. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires December 2025.