Last verified: 43 days ago
Grapeseed Extract
Also known as: GSE, Vitis vinifera seed extract, proanthocyanidins, OPC, oligomeric proanthocyanidins, flavanol-rich grapeseed extract, FRGSE
Evidence under review. — Not yet rated
Antioxidant-rich plant extract with weak clinical evidence. May help platelet function; most other claims are unproven.
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What it does
Grapeseed extract is a concentrated source of plant compounds called proanthocyanidins and flavanols, derived from the seeds of grapes. In a small clinical study, a single dose reduced platelet...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
No established dose from provided studies
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Found in
What the Science Says
Grapeseed extract is a concentrated source of plant compounds called proanthocyanidins and flavanols, derived from the seeds of grapes. In a small clinical study, a single dose reduced platelet stickiness in male smokers, which could theoretically support cardiovascular health. When combined with other nutrients alongside professional dental treatment, it showed modest improvements in gum pocket depth and bleeding — though grapeseed was not tested alone in that context.
What It Doesn't Do
Won't treat seasonal allergies — a clinical trial found zero benefit over placebo. Not proven to work as a standalone heart supplement in humans. No human evidence it protects against chemotherapy-related heart damage (that data is from rats only). Not a substitute for dental treatment. No proven benefit for female reproductive health in humans based on available data.
Evidence-Based Benefits
Grapeseed extract is a concentrated source of plant compounds called proanthocyanidins and flavanols, derived from the seeds of grapes. In a small clinical study, a single dose reduced platelet stickiness in male smokers, which could theoretically support cardiovascular health. When combined with other nutrients alongside professional dental treatment, it showed modest improvements in gum pocket depth and bleeding — though grapeseed was not tested alone in that context.
Weak EvidenceEffective at: No established dose from provided studies
Source: auto-research
Absorption & Bioavailability
Unknown — no pharmacokinetic data provided in the available studies. Absorption of proanthocyanidins is generally considered variable and dependent on molecular size.
Red Flags to Watch For
- Most products contain grapeseed extract as part of a multi-ingredient blend, making it impossible to attribute any benefit to grapeseed alone
- The only standalone clinical trial for allergic rhinitis showed no benefit over placebo
- Cardioprotective claims are based solely on rat studies — not human trials
- No standardized dose has been established across studies, making it hard to know if any product contains an effective amount
- Potential interaction with blood-thinning medications due to antiplatelet effects shown in the platelet study
Products Containing Grapeseed Extract
See how Grapeseed Extract is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-04-09