Last verified: 46 days ago
Grape Skin Extract
Also known as: muscadine grape skin extract, MPX, Vitis vinifera extract, anthocyanin oligomers, polyphenol grape extract, GSE
Evidence under review. — Not yet rated
Antioxidant-rich grape extract with modest eye health benefits; cancer and anti-aging claims lack solid human evidence.
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What it does
Grape skin extract is a concentrated source of polyphenols — including anthocyanins, resveratrol, ellagic acid, and quercetin — derived from grape skins. One randomized controlled trial found that...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
800–4000 mg daily depending on condition (limited data)
What the Science Says
Grape skin extract is a concentrated source of polyphenols — including anthocyanins, resveratrol, ellagic acid, and quercetin — derived from grape skins. One randomized controlled trial found that 800 mg/day improved symptoms of mild-to-moderate dry eye disease, including tear stability and eye surface health. Animal and lab studies suggest antioxidant and anti-inflammatory properties, but most of these findings have not been confirmed in rigorous human trials.
What It Doesn't Do
Does not treat or slow prostate cancer — a well-designed randomized trial was stopped early because it showed no benefit. Not proven to extend lifespan or reverse brain aging in humans. No solid evidence it improves memory or prevents Alzheimer's disease. Don't expect dramatic anti-aging skin results from this ingredient alone.
Evidence-Based Benefits
Grape skin extract is a concentrated source of polyphenols — including anthocyanins, resveratrol, ellagic acid, and quercetin — derived from grape skins. One randomized controlled trial found that 800 mg/day improved symptoms of mild-to-moderate dry eye disease, including tear stability and eye surface health. Animal and lab studies suggest antioxidant and anti-inflammatory properties, but most of these findings have not been confirmed in rigorous human trials.
Weak EvidenceEffective at: 800–4000 mg daily depending on condition (limited data)
Source: auto-research
Absorption & Bioavailability
Moderate/Unknown — A Caco-2 cell model study examined intestinal permeability of nine polyphenols in red grape skin extract, but human bioavailability data is limited. Polyphenol absorption varies significantly by compound and individual gut microbiome.
Red Flags to Watch For
- A large randomized controlled trial of muscadine grape skin extract for prostate cancer was stopped early due to futility — no benefit was found despite earlier promising signals
- Most compelling evidence (cancer prevention, brain aging, kidney protection) comes from animal or cell studies, not human trials
- Sold in over 1,000 registered supplement products, but clinical evidence for most marketed uses is very limited
- Dry eye benefit was shown in a single trial at 800 mg/day — results need independent replication before drawing firm conclusions
- Products vary widely in polyphenol content and standardization; 'grape skin extract' on a label doesn't guarantee any specific active compound level
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