“Proanthocyanidins (unspecified)?”Here!condensed tannins

Plant

Hasn’t appeared in a scanned product yet.

As a supplement

Talk to your doctor or pharmacist.

Roll Call does not check drug interactions or assess personal safety.

A broad class of plant polyphenols found in grape seeds, pine bark, cranberries, and many other fruits and barks. Listed as "unspecified," the label does not indicate which plant source or extract standardization was used.

Why it’s used

Taken by some for general antioxidant support, and sometimes for circulatory or vascular support, following research on specific proanthocyanidin-rich extracts.

What the evidence says

Named extracts — particularly grape seed extract and pine bark extract (Pycnogenol) — have been studied for antioxidant activity and, in smaller trials, for markers of vascular function. Findings are mixed and studies are often small or industry-funded. An unspecified proanthocyanidin ingredient carries none of that extract's defined chemistry or dosing, so the evidence for named extracts does not carry over cleanly.

Where we looked

There was no paper to cite here, so this is the search instead — run it yourself and see what we saw.

PubMed: 923 records · searched September 2026"Proanthocyanidins"[Title/Abstract] AND (review[pt] OR "safety assessment"[Title/Abstract] OR "risk assessment"[Title/Abstract] OR toxicology[Title/Abstract] OR toxicity[Title/Abstract] OR characterization[Title/Abstract] OR characterisation[Title/Abstract])
PubMed: 29 records · searched September 2026"Proanthocyanidins"[Title/Abstract] AND ("dietary supplements"[MeSH] OR supplementation[Title/Abstract] OR supplement[Title/Abstract] OR supplements[Title/Abstract] OR "oral administration"[Title/Abstract]) AND (randomized controlled trial[pt] OR clinical trial[pt] OR meta-analysis[pt] OR systematic review[pt]) AND humans[MeSH]
PubMed: 4247 records · searched September 2026"Proanthocyanidins"[Title/Abstract]

This says what this database holds under these terms. It is not a finding that no research exists.

Context

Evidence appears to exist, but mainly for specific standardized extracts (grape seed extract, Pycnogenol) rather than for "proanthocyanidins" generically. A reviewer resolving this would look for the named extract and its defined dose, not an unspecified compound class.

Rumors

1
Proanthocyanidins (OPCs) are 50 times more powerful antioxidants than vitamin E and 20 times more powerful than vitamin C.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- opc.cc — the site doesn’t say who runs it
2
Proanthocyanidins (PACs) block E. coli from attaching to the bladder wall, preventing urinary tract infections.
Supports — suggestivehealth and safety evidence
Measured as an outcome.
- Cranberries for preventing urinary tract infections (Peer-reviewed) · Funding not checked
- Preventive effect of cranberries with high dose of proanthocyanidins on urinary tract infections: a meta-analysis and systematic review (Peer-reviewed) · Funding not clearly stated · No conflicts declared
- Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study (Peer-reviewed) · Funded by Pharmatoka France (supplied capsules); INSERM Espri 26 supported by Université de Montpellier 1, La Ville de Nîmes, Le CHU de Nîmes, La Région Languedoc Roussillon · Authors declare a conflict of interest
Who’s saying this
- Utiva — a brand: sells pelvic health supplements for women
  How we know who this is
  “Today, Utiva is a leader in all things pelvic health and it is our only area of focus.” (their page)
  “With so much misinformation out there, we saw the need to create a company that offers both high-quality supplements and an educational platform to our customers so that they can make informed decisions.” (their page)
3
Proanthocyanidins affect blood clotting, so people with bleeding disorders, people due for surgery or people on blood thinners should avoid them.
Supports — suggestivehealth and safety evidence
Measured as a biomarker.
- Pine bark extract reduces platelet aggregation (Peer-reviewed) · Funding not checked
- Pine Bark Extract (Database) · Funding not checked
Who’s saying this
- Truemeds — a retailer: online pharmacy selling affordable substitute medicines
  How we know who this is
  “Truemeds, an e-pharmacy and telehealth platform, focuses on providing affordable substitute medicines” (their page)
4
Proanthocyanidins (OPC) increase collagen and elastin production in the skin, keeping it young.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- VitaminExpress — a retailer: sells a curated selection of other brands' products alongside its own
  How we know who this is
  “About VitaminExpress – Your Trusted Online Vitamin Shop” (their page)
  “The result is a carefully curated selection of trusted brands and products developed with our own expertise.” (their page)
5
Proanthocyanidins treat varicose veins and venous insufficiency by improving blood flow in the legs.
We haven’t found evidence strong enough to support this or rule it out.
What was measured is not yet noted.
Who’s saying this
- Apollo Pharmacy — a retailer: online and retail pharmacy selling medicines and healthcare products
  How we know who this is
  “For over 42 years, Apollo Pharmacy has been providing you with genuine medicines round-the-clock, through 24-hour pharmacies.” (their page)
  “With more than 7,500 stores in India, Apollo Pharmacy is not just the largest online pharmacy store in India but in Asia as well.” (their page)