Grape Seed Extract
Research reviewed: Up until 03/2026
Grape Seed Extract (Vitis vinifera) is a dietary supplement with 11 published peer-reviewed studies involving 920 participants, researched for Cardiovascular & Blood Pressure, Antioxidant & Anti-inflammatory, Metabolic Health and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Cardiovascular & Blood Pressure
StrongAntioxidant & Anti-inflammatory
ModerateMetabolic Health
StrongSkin & Cognitive Health
StrongResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Cardiovascular & Blood Pressure
To evaluate grape seed extract on blood pressure in pre-hypertensive adults
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate grape seed extract on blood pressure in pre-hypertensive adults
Dose
300 mg/day grape seed extract
Participants
36 pre-hypertensive adults
Duration
4 weeks
Results
Significant reduction in systolic BP (5.6 mmHg, p=0.01) and diastolic BP (4.7 mmHg). Endothelial function markers improved. Heart rate unchanged.
How They Measured It
24-hr ambulatory blood pressure, endothelial function, heart rate
To assess the effect of grape seed extract on blood pressure
Study Type
Systematic review and meta-analysis
Purpose
To assess the effect of grape seed extract on blood pressure
Dose
100-800 mg/day
Participants
Meta-analysis of 16 RCTs (810 participants)
Duration
4-16 weeks
Results
Significant reduction in systolic BP (MD -2.8 mmHg) and diastolic BP (MD -2.1 mmHg) vs placebo. Larger reductions in younger, obese subjects.
How They Measured It
Systolic and diastolic BP across 16 RCTs
To evaluate grape seed OPC on cardiovascular markers in hyperlipidaemic adults
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate grape seed OPC on cardiovascular markers in hyperlipidaemic adults
Dose
400 mg/day grape seed OPC
Participants
40 adults with hyperlipidaemia
Duration
8 weeks
Results
Significant reduction in LDL oxidation (35%), CRP (27%), and total cholesterol (-9%). Endothelial function improved. Antioxidant capacity increased.
How They Measured It
LDL oxidation, lipid panel, endothelial function, CRP
Antioxidant & Anti-inflammatory
To assess grape seed extract on antioxidant status in healthy adults
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess grape seed extract on antioxidant status in healthy adults
Dose
200-400 mg/day grape seed extract
Participants
50 healthy adults
Duration
4 weeks
Results
Significant increase in plasma antioxidant capacity (TEAC +21%, p=0.01) and reduction in oxidative DNA damage. F2-isoprostanes reduced.
How They Measured It
TEAC, ORAC, 8-OHdG, F2-isoprostanes
To evaluate grape seed extract on exercise-induced oxidative stress and muscle damage
Study Type
Randomised, controlled trial
Purpose
To evaluate grape seed extract on exercise-induced oxidative stress and muscle damage
Dose
400 mg/day grape seed extract
Participants
30 trained athletes
Duration
4 weeks
Results
Significant attenuation of exercise-induced CK elevation (p=0.03) and oxidative stress markers. DOMS reported lower in grape seed group. Performance maintained.
How They Measured It
CK, MDA, ORAC, DOMS, muscular performance
Metabolic Health
To evaluate grape seed extract on insulin sensitivity in obese adults
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate grape seed extract on insulin sensitivity in obese adults
Dose
600 mg/day grape seed extract
Participants
45 obese adults with insulin resistance
Duration
12 weeks
Results
Significant improvement in HOMA-IR (-18%, p=0.03) and adiponectin levels. Fasting glucose and insulin both improved. CRP reduced.
How They Measured It
HOMA-IR, fasting insulin, fasting glucose, adiponectin
To assess grape seed extract on non-alcoholic fatty liver disease
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess grape seed extract on non-alcoholic fatty liver disease
Dose
400 mg/day grape seed extract
Participants
55 NAFLD patients
Duration
6 months
Results
Significant reduction in ALT (22%), AST (19%), and liver fat grade on ultrasound vs placebo. Triglycerides reduced by 16%. Liver health markers improved.
How They Measured It
ALT, AST, liver fat by ultrasound, lipid profile
Skin & Cognitive Health
To evaluate grape seed OPC on skin aging, elasticity and UV protection
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate grape seed OPC on skin aging, elasticity and UV protection
Dose
100 mg/day grape seed OPC
Participants
40 women aged 40-60
Duration
12 weeks
Results
Significant improvement in skin elasticity (+15%) and hydration. Wrinkle depth reduced by 16% vs placebo. UV-protective effects observed.
How They Measured It
Skin elasticity, hydration, wrinkle depth, collagen density
To evaluate grape seed extract on cognitive function and neuroprotection
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To evaluate grape seed extract on cognitive function and neuroprotection
Dose
200 mg/day grape seed extract
Participants
50 adults with age-related cognitive decline
Duration
12 weeks
Results
Significant improvement in attention and memory recall (p=0.03). Cerebral blood flow increased. MMSE scores improved by 1.5 points vs placebo.
How They Measured It
MMSE, attention tests, memory recall, cerebral blood flow
To assess grape seed extract on symptoms of chronic venous insufficiency
Study Type
Randomised, double-blind, placebo-controlled
Purpose
To assess grape seed extract on symptoms of chronic venous insufficiency
Dose
450 mg/day grape seed OPC
Participants
71 patients with chronic venous insufficiency
Duration
12 weeks
Results
Significant reduction in leg pain (p<0.001) and leg edema. CEAP classification improved. Venous capillary resistance increased. Quality of life improved.
How They Measured It
Leg pain VAS, edema circumference, CEAP classification
To summarize evidence for grape seed extract across health outcomes
Study Type
Systematic review and meta-analysis
Purpose
To summarize evidence for grape seed extract across health outcomes
Dose
Various
Participants
Systematic review of RCTs
Duration
Various
Results
Strong evidence for blood pressure reduction and antioxidant effects. Promising evidence for metabolic, cognitive and skin health. Well-tolerated with good safety profile.
How They Measured It
Systematic review and meta-analysis across indications
Frequently Asked Questions
Common questions about Grape Seed Extract research
There are currently 11 peer-reviewed studies on Grape Seed Extract (Vitis vinifera), involving 920 total participants. Research covers Cardiovascular health, Blood pressure, Antioxidant status and 2 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (9 human studies), and reported outcomes.
Grape Seed Extract has been researched for: Cardiovascular health, Blood pressure, Antioxidant status, Skin health, Cognitive function. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 9 out of 11 studies are human trials. Human trials carry more weight in our evidence scoring system.
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