Grape seed extract
Summary
Grape seed extract comes from wine grape seeds and is rich in proanthocyanidins. Pooled controlled trials found modest drops in blood pressure (about 2 mm Hg diastolic) and small falls in LDL cholesterol and triglycerides (grade C), with large differences between studies. NCCIH says it is generally well tolerated, but little is known about use in pregnancy.
Key facts
- Extract of wine grape seeds containing proanthocyanidins[1]
- Diastolic −2.20 mm Hg and heart rate −1.25 bpm across 19 trials; systolic change not significant[2]
- LDL −0.17 mmol/L and triglycerides −0.11 mmol/L across 11 RCTs; no change in total or HDL cholesterol[5]
- Lower malondialdehyde, oxidized LDL and hs-CRP across 19 trials[7]
- Generally well tolerated by mouth; little known about pregnancy and breastfeeding[1]
- 5 graded human outcomes on this page
- October 13, 2026
How it works
ProposedGrape seed extract's proanthocyanidins are polyphenols with antioxidant activity. Pooled trials show reduced lipid-peroxidation markers, and lab work on endothelial cells found lower adhesion molecules and endothelin-1, proposed links to its small blood pressure effect.[1][7][8]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Blood pressure | Grade C | Improved | Meta-analysis of 19 trials · n = 1,080 · 2022 | 3 rows |
| Cholesterol | Grade C | Improved | Meta-analysis of 11 trials · n = 536 · 2020 | 1 row |
| Blood sugar | Grade D | Mixed | Crossover RCT · n = 32 · 2009 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Blood pressure and heart rate (pooled controlled trials) | Improved | Grade C | Meta-analysis · n = 1,080 · 2022 Adults in controlled trials Form: Grape seed extract · Dose: Varied; dose and duration shaped the effect · Duration: Varied Diastolic pressure fell 2.20 mm Hg and heart rate 1.25 bpm; systolic pressure (−3.55 mm Hg) and flow-mediated dilation did not change significantly. Heterogeneity was high. | 34798267 (opens PubMed)Source [2] |
| Systolic and diastolic blood pressure (pooled RCTs) | Improved | Grade C | Meta-analysis · n = 810 · 2016 Adults in randomized trials; larger effects in younger, obese or metabolic-syndrome groups Form: Grape seed extract · Dose: Varied across trials · Duration: Varied Systolic pressure fell 6.08 mm Hg and diastolic 2.80 mm Hg; no sign of publication bias. | 27537554 (opens PubMed)Source [3] |
| LDL cholesterol and triglycerides (pooled RCTs) | Improved | Grade C | Meta-analysis · n = 536 · 2020 Adults in randomized trials Form: Grape seed extract · Dose: Varied; effects on total and HDL cholesterol only in trials under 300 mg/day or under 10 weeks · Duration: Varied LDL fell 0.17 mmol/L (about 6.6 mg/dL) and triglycerides 0.11 mmol/L; total and HDL cholesterol did not change overall. | 32138795 (opens PubMed)Source [5] |
| Blood pressure, heart rate, lipids and CRP (early pooled RCTs) | Mixed | Grade C | Meta-analysis · n = 390 · 2011 Adults in randomized trials Form: Grape seed extract · Dose: Varied across trials · Duration: Varied Systolic pressure fell 1.54 mm Hg and heart rate 1.42 bpm; no effect on diastolic pressure, lipids or CRP. | 21802563 (opens PubMed)Source [4] |
| Blood-sugar and inflammation markers in type 2 diabetes | Mixed | Grade D | Crossover RCT · n = 32 · 2009 Obese adults with type 2 diabetes at high cardiovascular risk Form: Grape seed extract · Dose: 600 mg/day · Duration: 4 weeks per period Fructosamine and hsCRP fell and glutathione rose after grape seed extract but not placebo; endothelial function and insulin resistance did not change. | 19646193 (opens PubMed)Source [6] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Grape seed extract (proanthocyanidins) | Varies[1][8] | No human absorption figures in the cited sources; extracts are standardized to polyphenols, mainly proanthocyanidins.[1][8] | NCCIH describes grape seed extract as generally well tolerated by mouth.[1] | Blood pressure, lipid and diabetes trials (300–600 mg/day) |
| Whole-grape polyphenol products (juice, powders, skins) | Varies[9] | Not studied for absorption in the cited sources.[9] | No safety concerns raised in the pooled blood pressure analysis.[9] | Blood pressure (pooled grape polyphenol trials) |
Studied doses
Doses studied in human trials ranged from 300 mg/day for 16 weeks to 600 mg/day for 4 weeks in individual trials; pooled lipid analyses found total and HDL cholesterol changes only in trials under 300 mg/day.[8][6][5]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Pregnancy and breastfeeding
- Little is known about whether grape seed extract is safe during pregnancy or breastfeeding.[1]
- People on prescription medicines
- NCCIH advises checking with a health care provider, since some herbs and medicines interact.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
How to read the label
Cost per studied dose, without the sales pitch
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Cost per studied dose
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Frequently asked questions
Does grape seed extract lower blood pressure?
Modestly. The largest pooled analysis (19 trials) found diastolic pressure fell about 2.2 mm Hg, but systolic pressure did not change significantly.[2]
Does grape seed extract lower cholesterol?
Slightly. Eleven RCTs showed LDL fell about 0.17 mmol/L and triglycerides 0.11 mmol/L, with no overall change in total or HDL cholesterol.[5]
Is grape seed extract safe?
NCCIH says it is generally well tolerated by mouth or on the skin. Little is known about safety in pregnancy or breastfeeding.[1]
Is grape seed extract the same as resveratrol?
No. Grape seed extract is rich in proanthocyanidins; resveratrol is a different polyphenol and has its own page.[1]
Sources
- [1]Grape Seed Extract: Usefulness and Safety. NCCIH, 2025. fact-sheet
- [2]The effect of grape (Vitis vinifera) seed extract supplementation on flow-mediated dilation, blood pressure, and heart rate: A systematic review and meta-analysis of controlled trials with duration- and dose-response analysis.. Pharmacol Res, 2022. meta-analysis
- [3]The impact of grape seed extract treatment on blood pressure changes: A meta-analysis of 16 randomized controlled trials.. Medicine (Baltimore), 2016. meta-analysis
- [4]The effect of grape seed extract on cardiovascular risk markers: a meta-analysis of randomized controlled trials.. J Am Diet Assoc, 2011. meta-analysis
- [5]Effects of grape seed extract on dyslipidaemia: a systematic review and dose-response meta-analysis of randomised controlled trials.. Br J Nutr, 2020. meta-analysis
- [6]Effects of grape seed extract in Type 2 diabetic subjects at high cardiovascular risk: a double blind randomized placebo controlled trial examining metabolic markers, vascular tone, inflammation, oxidative stress and insulin sensitivity.. Diabet Med, 2009. crossover-RCT
- [7]The effect of grape seed extract supplementation on oxidative stress and inflammation: A systematic review and meta-analysis of controlled trials.. Int J Clin Pract, 2021. meta-analysis
- [8]Grape Seed Extract Positively Modulates Blood Pressure and Perceived Stress: A Randomized, Double-Blind, Placebo-Controlled Study in Healthy Volunteers.. Nutrients, 2021. RCT
- [9]Effect of Grape Polyphenols on Blood Pressure: A Meta-Analysis of Randomized Controlled Trials.. PLoS One, 2015. meta-analysis
What changed
- Adversarial review pass: every evidence row's numbers re-checked against its abstract (Europe PMC for abstracts PubMed truncates, PMC full text where open), grades checked against the grading rubric, and safety and overclaim wording re-read. No changes needed.
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.
- Strict second-pass self review (no separate reviewer agent was available for this batch): every PMID re-fetched via esummary and every evidence row, dose and safety line re-read against its abstract or fact sheet. NCCIH grape seed extract fact sheet (last updated February 2025) re-read; its participant count (1,080) is used for the 2022 meta-analysis. Slug 'grape' substituted from the queue (index 200) for a duplicate in the assigned list and scoped to grape seed extract. Retraction and erratum flags checked on all PMIDs: none.