20 Best Proanthocyanidins Supplements [2025]

Are you looking for the best proanthocyanidins supplements? Based on expert reviews, we ranked them. We've listed our top-ranked picks, including the top-selling proanthocyanidins supplements.

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1 Pine Bark Extract | 6000 mg | 180 Capsules | Standardized to Contain 95% Proanthocyanidins |... Pine Bark Extract | 6000 mg | 180 Capsules | Standardized to Contain 95% Proanthocyanidins |...
2 Zazzee Grape Seed Extract 20,000 mg Strength, 180 Vegan Capsules, 95% Polyphenols... Zazzee Grape Seed Extract 20,000 mg Strength, 180 Vegan Capsules, 95% Polyphenols...
3 NOW Supplements, Mannose Cranberry, Dual Action Formula*, Clinically Evaluated, Urinary Tract... NOW Supplements, Mannose Cranberry, Dual Action Formula*, Clinically Evaluated, Urinary Tract...
4 BRI Nutrition Grapeseed Extract - 400mg Maximum Strength 95% Proanthocyanidins Standardized Extract... BRI Nutrition Grapeseed Extract - 400mg Maximum Strength 95% Proanthocyanidins Standardized...
5 NOW Supplements, Pycnogenol 30 mg (a Unique Combination of Proanthocyanidins from French Maritime... NOW Supplements, Pycnogenol 30 mg (a Unique Combination of Proanthocyanidins from French Maritime...
6 Maui Herbs French Maritime Pine Bark Extract - Blood Flow Supplement, Heart Health & Healthy Skin... Maui Herbs French Maritime Pine Bark Extract - Blood Flow Supplement, Heart Health & Healthy Skin...
7 CranCap Cranberry Supplement for Urinary Tract Health | 36mg PAC | Made from Whole Cranberries |... CranCap Cranberry Supplement for Urinary Tract Health | 36mg PAC | Made from Whole Cranberries |...
8 ellura 36 mg PAC (30 caps) – Highly Effective Urinary Tract Supplement ellura 36 mg PAC (30 caps) – Highly Effective Urinary Tract Supplement
9 NOW Supplements, Pycnogenol 30 mg (a Unique Combination of Proanthocyanidins from French Maritime... NOW Supplements, Pycnogenol 30 mg (a Unique Combination of Proanthocyanidins from French Maritime...
10 NOW Supplements, Pycnogenol 100 mg (a Unique Combination of Proanthocyanidins from French Maritime... NOW Supplements, Pycnogenol 100 mg (a Unique Combination of Proanthocyanidins from French...
11 Grape Seed Extract - 400 mg - 95% Polyphenols Proanthocyanidins - 120 Veggie Capsules - All Natural... Grape Seed Extract - 400 mg - 95% Polyphenols Proanthocyanidins - 120 Veggie Capsules - All...
12 NOW Supplements, Cranberry with PACs, plus Uva Ursi and Grape Seed Extracts 90 Veg Capsules NOW Supplements, Cranberry with PACs, plus Uva Ursi and Grape Seed Extracts 90 Veg Capsules
13 Swanson Grape Seed Heart Antioxidant Free Radicals Healthy Blood Pressure Support Polyphenols OPCS... Swanson Grape Seed Heart Antioxidant Free Radicals Healthy Blood Pressure Support Polyphenols...
14 Grape Seed Extract 300mg x 180 Tablets - 90% Oligomeric Proanthocyanidins. 300% Stronger Than... Grape Seed Extract 300mg x 180 Tablets - 90% Oligomeric Proanthocyanidins. 300% Stronger Than...
15 OptiHealth OPCXtra Isotonic OPC - 3 Month Supply - Grape Seed Extract, Pine Bark Extract, Red Wine... OptiHealth OPCXtra Isotonic OPC - 3 Month Supply - Grape Seed Extract, Pine Bark Extract, Red...
16 Cranberex Cranberry Concentrate Supplement Pills | Cranberry Extract Capsules for Urinary Tract... Cranberex Cranberry Concentrate Supplement Pills | Cranberry Extract Capsules for Urinary Tract...
17 TheraCran One Cranberry Supplement | 36mg PACs Per Capsule | 90 Day Supply | Cranberry Extract,... TheraCran One Cranberry Supplement | 36mg PACs Per Capsule | 90 Day Supply | Cranberry Extract,...
18 Utiva Cranberry PACs, by Szio+ Inc. - 30 Vegi Caps – 36 mg Soluble PACs DMAC/A2; Promoting a... Utiva Cranberry PACs, by Szio+ Inc. - 30 Vegi Caps – 36 mg Soluble PACs DMAC/A2; Promoting a...
19 One A Day Cranberry Promotes Urinary Health by Cleansing The Urinary Tract, 120 ct by Puritan's... One A Day Cranberry Promotes Urinary Health by Cleansing The Urinary Tract, 120 ct by Puritan's...
20 Pure Synergy SuperPure Grape Seed Extract | 60 Capsules | Certified Organic | Non-GMO | Vegan |... Pure Synergy SuperPure Grape Seed Extract | 60 Capsules | Certified Organic | Non-GMO | Vegan |...
Bestseller No. 1
Pine Bark Extract | 6000 mg | 180 Capsules | Standardized to Contain 95% Proanthocyanidins |...
  • STANDARDIZED FORMULA: Pink Bark standardized to contain 380 mg Proanthocyanidins per capsule
  • PINE BARK: The equivalent of 6,000 mg of Pine Bark in each quick-release capsule
  • EXPERTLY CRAFTED: Our professional formula is backed by our commitment to purity and potency
  • HORBAACH MANUFACTURERS: Laboratory Tested, Trusted Ingredients, Superior Quality, 100% Guaranteed!
  • NATURALLY FREE OF: Gluten, Wheat, Yeast, Lactose, Soy, Artificial Flavor, Preservatives & Non-GMO
Bestseller No. 2
Zazzee Grape Seed Extract 20,000 mg Strength, 180 Vegan Capsules, 95% Polyphenols...
  • MAXIMUM VALUE / MAXIMUM STRENGTH: Each bottle contains 180 veggie capsules, each capsule contains a robust 400 mg of a potent 50:1 Grape Seed Extract,...
  • POTENT ANTIOXIDANT SUPPORT: At 400 mg per capsule of a concentrated, highly standardized 50:1 extract, our Grape Seed Extract offers a large dose of...
  • HIGH BIOAVAILABILITY, HIGHLY CONCENTRATED AND ALL-NATURAL: Our Grape Seed Extract is a highly concentrated, standardized 50:1 extract containing a...
  • 100% VEGETARIAN: All ingredients, as well as the capsules, are 100% vegetarian, and made from the purest sources available. The capsules are made from...
  • GOLD STANDARD PRODUCTION: Your health and safety mean everything to us. For that reason, our Grape Seed Extract is manufactured in the USA, in a fully...
Bestseller No. 3
NOW Supplements, Mannose Cranberry, Dual Action Formula*, Clinically Evaluated, Urinary Tract...
  • Mannose Cranberry is a combination of two ingredients known to support urinary tract (UT) health
  • Both Mannose and Proanthocyanidins (PACs) (the main active constituents from Cranberry) possess properties that promote the maintenance of a clean...
  • This product features a proprietary blend of whole Cranberry fruit with a unique PAC profile that has clinically demonstrated its ability to help...
Bestseller No. 4
BRI Nutrition Grapeseed Extract - 400mg Maximum Strength 95% Proanthocyanidins Standardized Extract...
  • ★ WHY US: We looked at all other Grape Seed Extract supplements on the market and were surprised by the low Proanthocyanidins count or the use of...
  • ★ NATURES ANTIOXIDANT POWERHOUSE: With 400mg pure Vitis Vinifera, every serving is loaded with oligomeric Proanthocyanidins standardized to 95%,...
  • ★ 100% VEGETARIAN & PURE: Our capsules are derived from plant cellulose, and all ingredients are derived from the purest plant-based sources.We use...
  • ★ EASY TO SWALLOW & EASY ON THE STOMACH: Our formulation provides a perfectly balanced dose that is easy to swallow and easy on your digestive...
  • ★ PURITY: BRI makes only premium, extra pure, high potency vitamins, capsules, pills, tablets, powders, multivitamins, supplements, topicals...
Bestseller No. 5
NOW Supplements, Pycnogenol 30 mg (a Unique Combination of Proanthocyanidins from French Maritime...
  • FREE RADICAL SCAVENDER*/WITH 300 mg BIOFLAVONOIDS: As a potent natural scavenger of free radicals, Pycnogenol helps to protect the body's tissues from...
  • HEALTHY VASCULAR FUNCTION*/BALANCED IMMUNE RESPONSE*: Scientific studies have shown that Pycnogenol helps to maintain vascular strength and function.*...
  • CLASSIFICATIONS/CERTIFICATIONS: Non-GMO, Kosher, Corn Free, Dairy Free, Egg Free, Made without Gluten, Nut Free, Soy Free, Vegan/Vegetarian
  • GMP Quality Assured: NOW closely adheres to both mandatory U.S. FDA Current Good Manufacturing Practices (CGMP) regulations and voluntary Natural...
  • Packaged in the USA by a family owned and operated company since 1968
Bestseller No. 6
Maui Herbs French Maritime Pine Bark Extract - Blood Flow Supplement, Heart Health & Healthy Skin...
  • Healthy Blood Support - Our French pine bark extract helps promote proper blood circulation. It helps promote blood flow, with nutrients aiding in...
  • Strengthen Your Heart - French pine bark extract has been shown to support the health of your heart, to support proper circulation, allowing blood to...
  • Skin Wellness & Proper Balance -These pine bark extract capsules helps support your skin. The compounds in this male and female health supplement may...
  • Nature’s Antioxidant - Pine bark is naturally rich in proanthocyanidin as well as flavonoids and other antioxidants. It is also loaded with...
  • Natural and Pure - We use nothing but organic plants sourced from the wild in a sustainable manner - choice ingredients that are treated and processed...
Bestseller No. 7
CranCap Cranberry Supplement for Urinary Tract Health | 36mg PAC | Made from Whole Cranberries |...
  • HIGHLY RECOMMENDED - What most people say after trying CranCap whole fruit supplement after years of struggling with the pain, discomfort, worry, and...
  • QUALITY MATTERS - While other cranberry supplements are made from the skins, seeds and stems of cranberries, high quality CranCap is made from the...
  • NURSE OWNED - CranCap is made by 2 women that support other female owned businesses. We only specialize in proven healthcare solutions that are backed...
  • USAGE - Only 1 capsule a day is needed for powerful urinary tract health you can trust. This supplement can be used by both men and women. Do not use...
  • GUARANTEE - 100% satisfaction guaranteed. We are so confident that CranCap 36mg PAC whole fruit cranberry supplements are quality you can trust, we...
Bestseller No. 8
ellura 36 mg PAC (30 caps) – Highly Effective Urinary Tract Supplement
  • Derived from nature and boosted by science, ellura provides the highest levels of medical grade PAC (proanthocyanidins) needed to maintain a clean...
  • Only ellura is made from pure cranberry juice extract, making it both highly potent and highly effective at helping to maintain a clean urinary tract....
  • Multiple scientific studies have shown ellura to have the most potent PAC compared to other supplements. Not all PAC are created equal.
  • ellura starts working within hours of taking just one capsule.
  • Urologist recommended.
Bestseller No. 9
NOW Supplements, Pycnogenol 30 mg (a Unique Combination of Proanthocyanidins from French Maritime...
  • FREE RADICAL SCAVENGER*/WITH 300 mg BIOFLAVONOIDS: As a potent natural scavenger of free radicals, Pycnogenol helps to protect the body's tissues from...
  • HEALTHY VASCULAR FUNCTION*/BALANCED IMMUNE RESPONSE*: Scientific studies have shown that Pycnogenol helps to maintain vascular strength and function.*...
  • CLASSIFICATIONS/CERTIFICATIONS: Non-GMO, Kosher, Corn Free, Dairy Free, Egg Free, Made without Gluten, Nut Free, Soy Free, Vegan/Vegetarian
  • GMP Quality Assured: NOW closely adheres to both mandatory U.S. FDA Current Good Manufacturing Practices (CGMP) regulations and voluntary Natural...
  • Packaged in the USA by a family owned and operated company since 1968
Bestseller No. 10
NOW Supplements, Pycnogenol 100 mg (a Unique Combination of Proanthocyanidins from French Maritime...
  • FREE RADICAL SCAVENGER*/WITH 240 mg AMLA EXTRACT: NOW Pycnogenol 100 mg supports a healthy, balanced immune system response, and promotes the...
  • Product Note: Exposure to heat or sunlight may lead to melting/damage of product. Hence customers are expected to be available during the product...
  • HEALTHY VASCULAR FUNCTION*/BALANCED IMMUNE RESPONSE*: Clinical and non-clinical studies have demonstrated that Pycnogenol can help to maintain healthy...
  • CLASSIFICATIONS/CERTIFICATIONS: Non-GMO, Kosher, Dairy Free, Egg Free, Made without Gluten, Nut Free, Soy Free, Vegan/Vegetarian
  • GMP Quality Assured: NOW closely adheres to both mandatory U.S. FDA Current Good Manufacturing Practices (CGMP) regulations and voluntary Natural...
Bestseller No. 11
Grape Seed Extract - 400 mg - 95% Polyphenols Proanthocyanidins - 120 Veggie Capsules - All Natural...
  • THE MOST POTENT ANTIOXIDANT: Grape seeds are extremely rich in antioxidants, including phenolic acids, anthocyanins, flavonoids, and oligomeric...
  • THE BENEFITS; Grapeseed extract is a natural antioxidant which helps promoting internal health by fighting free radical damage. Among many of its...
  • MORE BANG FOR YOUR BUCK: Our extract is standardized to contain more than 95% proanthocyanidins which is equivalent to more than 20,000 mg of grape...
  • BEST INGREDIENTS - HIGHEST QUALITY; Our vegetarian capsules contain 400mg of pure Grape Seed Extract containing natural polyphenols standardized to...
  • 100% SATISFACTION GUARANTEE - MADE IN USA; formulated by experts & made in the USA following strict GMP guidelines. This product is tested for purity,...
SaleBestseller No. 12
NOW Supplements, Cranberry with PACs, plus Uva Ursi and Grape Seed Extracts 90 Veg Capsules
  • HEALTHY URINARY TRACT*: Cranberry has become an essential component in the promotion of sound urinary tract health*
  • CLEANSES THE URINARY TRACT*: Cranberry has naturally occurring compounds called proanthocyanidins (PACs) that help to maintain a clean waste stream*
  • ADDED SUPPORT: For added support, we’ve also included 300 mg of uva ursi extract and 45 mg of grape seed extract
  • GMP Quality Assured: NPA A-rated GMP certification means that every aspect of the NOW manufacturing process has been examined, including our...
  • Packaged in the USA by a family owned and operated company since 1968
SaleBestseller No. 13
Swanson Grape Seed Heart Antioxidant Free Radicals Healthy Blood Pressure Support Polyphenols OPCS...
  • ANTIOXIDANT, FREE RADICAL DEFENSE - Grape seed extract delivers a generous amount of something called Oligomeric proanthocyanidins or OPCs for short,...
  • ANTI-AGING PROPERTIES - The polyphenol benefits in grape seed extract are excellent for skin health and anti-aging effects. Polyphenols are great for...
  • SUPPORTS HEALTHY BLOOD PRESURE WITHIN THE NORMAL RANGE - The high Oligomeric proanthocyanidins content in grape seed extract has been shown in various...
  • 100% MONEY BACK GUARANTEE - Our products reflect our commitment to giving you the best quality and service at the best price. We guarantee that every...
  • OUR QUALITY & HERITAGE - We're control freaks...in a good way! For nearly 50 years, Swanson Health has delivered science-backed health products...
Bestseller No. 14
Grape Seed Extract 300mg x 180 Tablets - 90% Oligomeric Proanthocyanidins. 300% Stronger Than...
  • 300mg Grape Seed Extract per tablet - 3 times stronger than normal tablets/capsules
  • 90% Oligomeric Proanthocyanidins compared to the usual 50%
  • Each bottle will last 3 months
  • Grape seed extract is regarded as one of the wonders of mother nature
  • Sold by a reputable 10 year old company
Bestseller No. 15
OptiHealth OPCXtra Isotonic OPC - 3 Month Supply - Grape Seed Extract, Pine Bark Extract, Red Wine...
  • Highest Potency OPC Extracts - OPCXtra contains 180mg of combined standardized OPC extracts, more than any other Isotonic OPC product on the market....
  • Natural Health Support - A healthy immune system is your bodies best defense. Antioxidants are powerful immune support supplements that occur in...
  • Easy to Use Powdered Formulation - Taking care of your health should be simple and easy. Pills, tablets, gummies and chewable vitamin formulations and...
  • Health Support for Men & Women - Maintaining your health at all stages of your adult life is important. OPCXtra isotonic supplements provide powerful...
  • We Stand for Health - All of our products are made in the USA. Our products are 100% natural, non-gmo, vegetarian, vegan, and free from all gluten,...
Bestseller No. 16
Cranberex Cranberry Concentrate Supplement Pills | Cranberry Extract Capsules for Urinary Tract...
  • 36 mg PAC (A-TYPE) promotes a healthy/clear urinary tract.
  • ALL NATURAL: Gelatin-Free, Non-GMO, Vegan, Gluten-Free Ingredients that include No Sugar or Dairy.
  • CONVENIENT 2 MONTH SUPPLY: 60 easy to swallow clinical grade Cranberex capsules per bottle. Can be taken once or twice a day with a meal or on an...
  • PROANTHOCYANIDINS: Extract made from 100% Oregon Cranberries and contains 36 mg PACs per dose.
  • SOLAR POWERED MANUFACTURING: Every purchase supports our employee-owned business that operates out of our solar-powered, NSF certified facility in...
Bestseller No. 17
TheraCran One Cranberry Supplement | 36mg PACs Per Capsule | 90 Day Supply | Cranberry Extract,...
  • CONSUMERLAB TOP PICK: selected as the 2021 Top Pick by ConsumerLab among cranberry supplements, containing the highest level of PACs with the lowest...
  • EVIDENCE-BASED FORMULA & DOSING: Contains 36 mg of PACs per capsule, the amount that has been shown in scientific studies to promote urinary tract...
  • WHOLE CRANBERRY EXTRACT: Made from cranberry juice, flesh, skins, and seeds to provide a balanced spectrum of PACs and other active cranberry...
  • TESTED AND CERTIFIED: The only cranberry supplement that is independently tested and certified (NSF International) in the USA for content accuracy,...
  • QUALITY: Made in the USA in a cGMP compliant facility. Physician formulated and backed by Theralogix’ Medical Advisory Board.
Bestseller No. 18
Utiva Cranberry PACs, by Szio+ Inc. - 30 Vegi Caps – 36 mg Soluble PACs DMAC/A2; Promoting a...
  • Utiva UTI Control is now called Utiva Cranberry PACs and provides the same 36 mg of soluble PACs ** PROMOTE BLADDER HEALTH: Whether you are suffering...
  • 100% NATURAL AND VEGAN: At Utiva we strive to bring the best ingredients when producing our all-natural, non-GMO, gluten-free and cranberry...
  • 36MG SOLUBLE PACS: Our doctor recommended cranberry extract supplement is packed with 36mg’s of soluble proanthocyanidins (PACs) from real...
  • HIGH QUALITY AND LOCALLY MADE: Not all cranberry supplements are the same, the use of the DMAC/A2 method in our active ingredients (soluble PACs)...
  • URINARY CARE FOR ALL AGES: There can be a stigma around (UTI)’s or urinary tract infections, not drinking enough fluids, menopause or having an...
Bestseller No. 19
One A Day Cranberry Promotes Urinary Health by Cleansing The Urinary Tract, 120 ct by Puritan's...
  • Highest quality vitamins and supplements since 1973
  • Helps cleanse the urinary tract by removing unwanted compounds. Health Concern: Urinary Tract Support
  • Contains proanthocyanides (PACS), the active components that deliver cranberry's benefits
  • Non-GMO & Gluten Free
  • 4 month supply
Bestseller No. 20
Pure Synergy SuperPure Grape Seed Extract | 60 Capsules | Certified Organic | Non-GMO | Vegan |...
  • 150 mg of Proanthocyanidins/OPCs and 250 mg of Polyphenols per capsule derived from organic grape seeds and organic red wine grape skins
  • Support for: healthy, strong blood vessels; cholesterol/blood pressure already within a normal range; healthy radiant skin and eyes, and much more!
  • Whole-spectrum, synergistic formula with proanthocyanidins, anthocyanins, catechins and epicatechins
  • Certified Organic; SuperPure Extract Processing (zero tolerance for chemical solvents and additives); Non-GMO, Vegan, Allergen-Free

Having trouble finding a great proanthocyanidins supplements?

This problem is well understood by us because we have gone through the entire proanthocyanidins supplements research process ourselves, which is why we have put together a comprehensive list of the best proanthocyanidins supplementss available in the market today.

After hours of searching and using all the models on the market, we have found the best proanthocyanidins supplements for 2023. See our ranking below!

How Do You Buy The Best Proanthocyanidins Supplements?

Do you get stressed out thinking about shopping for a great proanthocyanidins supplements? Do doubts keep creeping into your mind?

We understand, because we’ve already gone through the whole process of researching proanthocyanidins supplements, which is why we have assembled a comprehensive list of the greatest proanthocyanidins supplements available in the current market. We’ve also come up with a list of questions that you probably have yourself.

John Harvards has done the best we can with our thoughts and recommendations, but it’s still crucial that you do thorough research on your own for proanthocyanidins supplements that you consider buying. Your questions might include the following:

  • Is it worth buying an proanthocyanidins supplements?
  • What benefits are there with buying an proanthocyanidins supplements?
  • What factors deserve consideration when shopping for an effective proanthocyanidins supplements?
  • Why is it crucial to invest in any proanthocyanidins supplements, much less the best one?
  • Which proanthocyanidins supplements are good in the current market?
  • Where can you find information like this about proanthocyanidins supplements?

We’re convinced that you likely have far more questions than just these regarding proanthocyanidins supplements, and the only real way to satisfy your need for knowledge is to get information from as many reputable online sources as you possibly can.

Potential sources can include buying guides for proanthocyanidins supplements, rating websites, word-of-mouth testimonials, online forums, and product reviews. Thorough and mindful research is crucial to making sure you get your hands on the best-possible proanthocyanidins supplements. Make sure that you are only using trustworthy and credible websites and sources.

John Harvards provides an proanthocyanidins supplements buying guide, and the information is totally objective and authentic. We employ both AI and big data in proofreading the collected information.

How did we create this buying guide? We did it using a custom-created selection of algorithms that lets us manifest a top-10 list of the best available proanthocyanidins supplements currently available on the market.

This technology we use to assemble our list depends on a variety of factors, including but not limited to the following:

  1. Brand Value: Every brand of proanthocyanidins supplements has a value all its own. Most brands offer some sort of unique selling proposition that’s supposed to bring something different to the table than their competitors.
  2. Features: What bells and whistles matter for an proanthocyanidins supplements?
  3. Specifications: How powerful they are can be measured.
  4. Product Value: This simply is how much bang for the buck you get from your proanthocyanidins supplements.
  5. Customer Ratings: Number ratings grade proanthocyanidins supplements objectively.
  6. Customer Reviews: Closely related to ratings, these paragraphs give you first-hand and detailed information from real-world users about their proanthocyanidins supplements.
  7. Product Quality: You don’t always get what you pay for with an proanthocyanidins supplements, sometimes less, and sometimes more.
  8. Product Reliability: How sturdy and durable an proanthocyanidins supplements is should be an indication of how long it will work out for you.

John Harvards always remembers that maintaining proanthocyanidins supplements information to stay current is a top priority, which is why we are constantly updating our websites. Learn more about us using online sources.

If you think that anything we present here regarding proanthocyanidins supplements is irrelevant, incorrect, misleading, or erroneous, then please let us know promptly!

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FAQ:

Q: Are proanthocyanidins a sustainable source of dietary supplements and functional ingredients?

A: Agricultural wastes and food processing wastes contain immense amount of proanthocyanidins, exploitation of which can be a sustainable source of dietary supplements and functional ingredients. The current review article discusses recent developments in the health promoting properties of proanthocyanidins and the associated hurdles.

Q: What should you look for when buying proanthocyanidins?

A: As mentioned above, you’re going to want to look for supplements that contain approximately 175mg of proanthocyanidins per gram. At that dosage, it’s been shown to reduce the appearance of infections.

Q: What fruits have proanthocyanidins?

A: Proanthocyanidins is present in medlar, mulberry, plum, apricot, walnut, silverberry, pomegranate as well i.e. its ubiquitous to all most all fruits [ 12 ]. Grape seed proanthocyanidins are consumed as dietary supplements.

Q: How much proanthocyanidins do you need to prevent bacterial infection?

A: That supplement contained 175mg of proanthocyanidins per gram and was also shown to prevent bacterial growth in culture. Four of the tested supplements contained less than 5mg of proanthocyanidins per gram and had no impact on bacterial infection.