Grape seed (Vitis vinifera): Uses, Evidence and Safety
Grape seed extract (Vitis vinifera): what reviews found for blood pressure and cholesterol, what is only lab work, and the blood-thinner, medicine and pregnancy cautions.
Content last updated . This page has not been medically reviewed.
Safety first. Natural products can cause side effects and interact with medicines. Read herb safety and interactions before you use anything on this page.
What is Grape seed extract good for?
What the body uses it for, and how strong the evidence is. A normal job in the body is not proof that extra supplements add benefit; each card says which.
Blood pressure and heart rate
Preliminary or mixedTwo meta-analyses found small falls in blood pressure; they disagreed on systolic pressure. A 2022 review found diastolic pressure and heart rate fell slightly.
Supplements: Small, inconsistent effects; not a replacement for blood pressure treatment.
Blood cholesterol and triglycerides
Preliminary or mixedA 2020 review of 11 trials found a small fall in LDL cholesterol and triglycerides but no overall change in total or HDL cholesterol. NCCIH calls this not definitive.
Supplements: Possible small effect on LDL and triglycerides; not shown to replace cholesterol medicines.
Blood sugar and inflammation markers
Preliminary or mixedMSK says results for sugar and inflammation markers are mixed.
Supplements: No clear benefit shown in the sources read.
Antioxidant activity
Lab or animal research onlyThe extract is marketed for antioxidant properties and rich in proanthocyanidins; MSK describes this mostly through lab and early studies.
Supplements: No proven benefit for people from this property in the sources read.
Heart protection (lab research)
Lab or animal research onlyMSK describes protective effects on the heart in preclinical (lab and animal) work, including against a chemotherapy drug's heart toxicity.
Supplements: Not shown in people in the sources read.
Wound healing and tooth decay
Lab or animal research onlyNCCIH says animal studies on wound healing look promising and lab work suggests a mouthrinse could help, but human research is too limited to judge.
Supplements: Insufficient human evidence.
Radiotherapy breast tissue hardening
Not enough evidenceOne trial of the oral extract found no improvement in tissue hardness, pain or tenderness after breast radiotherapy.
Supplements: No good evidence of benefit.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (3)
- Blood Pressure SupportPreliminary or mixed
Two meta-analyses found small blood pressure falls but disagreed on systolic pressure, so evidence is mixed.
- Cholesterol BalancePreliminary or mixed
A 2020 review found a small fall in LDL and triglycerides but not in total or HDL cholesterol; NCCIH says not definitive.
- Heart HealthPreliminary or mixed
Blood pressure and cholesterol markers moved slightly in some trials; no trials on heart attacks or strokes were found in the sources read.
Body systems (2)
- Cardiovascular SystemPreliminary or mixed
Small, inconsistent effects on blood pressure and blood fats in trials.
- Heart & CirculationPreliminary or mixed
Small, inconsistent effects on blood pressure and blood fats in trials.
Body parts (2)
- Blood VesselsPreliminary or mixed
The 2022 meta-analysis found no significant change in flow-mediated dilation (artery widening) and a small fall in diastolic pressure.
- HeartPreliminary or mixed
Heart rate fell slightly in a 2022 meta-analysis; heart protection findings in MSK are lab-based.
Functional actions (2)
- Cardiovascular SupportPreliminary or mixed
Studied for blood pressure and cholesterol with small, mixed effects.
- AntioxidantLab or animal research only
Marketed for antioxidant properties; MSK mentions raised blood antioxidant activity only as an early finding, not a health outcome.
Root causes (1)
- Medication Side EffectsDocumented risk
Possible bleeding risk with blood thinners and lab-based effects on drug-processing enzymes; clinical relevance not determined.
Biomarkers (3)
- LDL CholesterolPreliminary or mixed
A 2020 meta-analysis found a small fall in LDL; NCCIH says results are not definitive.
- TriglyceridesPreliminary or mixed
A 2020 meta-analysis found a small fall in triglycerides.
- HDL CholesterolPreliminary or mixed
No overall significant effect on HDL in the 2020 meta-analysis.
Documented risks and interactions (4)
- Bleeding risk with blood thinners. In lab tests the extract showed antiplatelet activity. MSK advises people on warfarin and similar drugs to talk with their provider because bleeding risk may rise.
- Changes in how some medicines are processed. In lab tests the extract inhibited the CYP3A4 enzyme and affected UGT enzymes, which could change levels or side effects of medicines handled that way.
- Pregnancy and breastfeeding. NCCIH says safety in pregnancy and breastfeeding is not well established and little is known.
- Stomach and gut upset. MSK's clinician section lists gastrointestinal upset; NCCIH says the extract is generally well tolerated.
Safety first: blood thinners and medicines come first
Memorial Sloan Kettering (MSK) says grape seed extract showed antiplatelet activity (it can make blood cells less sticky) in laboratory tests, which may raise the risk of bleeding, and it tells people taking blood thinners such as warfarin to talk with their provider first. [1] MSK also lists laboratory findings that the extract blocks an enzyme called CYP3A4 and affects UGT enzymes, which could change how some medicines behave. For each of these, MSK says the importance in real patients is not yet known. [1] The National Center for Complementary and Integrative Health (NCCIH) says safety in pregnancy and breastfeeding is not well established. [2] Tell your prescriber, pharmacist and surgical team about any grape seed product. See how herb and medicine interactions work and supplements before surgery.Look-alike warning: grape seed extract is not grapefruit seed extract. MSK says the two have different effects. [1]
Overview
Grape seed extract comes from the seeds of the wine grape, Vitis vinifera. GBIF lists Vitis vinifera as the accepted name, in the family Vitaceae. [6] NCCIH describes it as a supplement made from wine grape seeds, mostly marketed to lower blood cholesterol and blood pressure, and also used in some skin products. [2] MSK says it is a by-product of winemaking and is marketed for its antioxidant properties. [1] Its main compounds are proanthocyanidins, which also occur in fruit, vegetables, chocolate and tea. [1] The native range of the grape was not found in the sources we read. This page covers the seed extract; for the "OPC" label and pine bark extract, see grape seed and pine bark extracts.Traditional use (not proof of benefit)
The sources we read did not describe a traditional medicine use of grape seed extract. MSK lists the purported uses as lowering cholesterol, reducing inflammation and treating hardening of the arteries, and says other uses have not been studied. [1] These are marketing claims for a modern supplement, not proof.What research shows
Findings from the lab (cells and animals) are kept apart from human trials below.| Use | What the sources found | Strength of evidence | Form and population |
|---|---|---|---|
| Blood pressure | A 2016 meta-analysis of 16 trials (810 people) found systolic pressure fell by about 6.1 mmHg and diastolic by about 2.8 mmHg, mostly in younger, obese or metabolic-syndrome groups; the authors asked for larger, longer trials. [3] A 2022 meta-analysis of 19 trials found diastolic pressure fell about 2.2 mmHg and heart rate about 1.25 beats a minute, with no significant change in systolic pressure. [4] NCCIH reports the same 2022 result and says results varied. [2] | Mixed | Extract supplements; adults |
| Blood cholesterol and fats | A 2020 meta-analysis of 11 trials (536 people) found a small fall in LDL ("bad") cholesterol and triglycerides but no overall effect on total or HDL cholesterol. [5] NCCIH says this is not definitive because studies were small and products differed. [2] | Promising but limited | Extract supplements; adults |
| Other heart and blood markers | MSK says results for fats, sugar and inflammation markers are mixed. [1] | Mixed | Extract supplements |
| Breast tissue hardening after radiotherapy | One trial found no improvement in hardness, pain or tenderness. [1] | No good evidence of benefit | Oral extract; people with breast cancer |
| Wound healing and tooth decay | NCCIH: animal studies on wounds look promising, lab work on a mouthrinse is early, and human research is too limited to judge. [2] | Insufficient evidence | Skin and mouth products |
| Heart protection and cancer | MSK describes protective effects in preclinical (lab and animal) work only. [1] | Lab and animal findings only | Not human trials |
Effects on heart attacks, strokes or lifespan: Proper evidence not found in the sources we read.
Forms and why the form matters
Grape seed extract is sold as tablets, capsules and liquids. [1] Products are not identical: NCCIH notes that products varied across trials. [2] MSK says people generally consume about 460 to 1,000 mg a day of proanthocyanidins together from food, which is a dietary estimate, not advice. [1] Grape seed oil and whole grape seeds were not covered by the sources we read, so results should not be assumed for them. How much to use is a decision for a clinician or pharmacist.Safety in more detail
- Side effects: NCCIH says the extract is generally well tolerated by mouth or on the skin, without listing specific effects. [2] MSK's clinician section lists stomach and gut upset, while its patient section says no side effects have been reported. [1]
- Medicines: MSK flags blood thinners and antiplatelet drugs (bleeding), CYP3A4 and UGT-processed drugs (laboratory findings, relevance unknown). [1] NCCIH says anyone taking medicines should check first. [2] See how the body processes herbs.
- Pregnancy and breastfeeding: NCCIH says little is known and safety is not well established. [2] The MSK page we read did not address either.
- Children: not described in the sources we read.
- Liver and kidney: not described in the sources we read. We could not open the NIH LiverTox entry (the site blocked automated access), so we make no claim either way.
- Allergy and surgery: not described in the sources we read. Surgery teams usually want a full supplement list.
- Quality: NCCIH says products varied between studies. [2] See quality testing and certifications.
Official statements
- NCCIH (NIH, US), page updated February 2025: summary of uses, reviews and safety. [2]
- Memorial Sloan Kettering, page updated February 2022: summary of evidence and interactions. [1]
- EU herbal monograph or other regulator statements: Proper evidence not found in the sources we read.
Related pages
Frequently asked questions
Does grape seed extract lower blood pressure?
Two meta-analyses found small drops, but they disagreed on systolic pressure and trials varied widely. [3][4]
Does it lower cholesterol?
A 2020 meta-analysis found a small fall in LDL cholesterol and triglycerides, but not in total or HDL cholesterol. NCCIH says this is not definitive. [5][2]
Can I take it with warfarin or other blood thinners?
MSK advises talking with your provider first because lab tests suggest it may raise bleeding risk. [1]
Is grape seed extract safe in pregnancy?
NCCIH says safety in pregnancy and breastfeeding is not well established. [2]
Is it the same as grapefruit seed extract?
No. MSK says they have different effects. [1]
References
- Memorial Sloan Kettering Cancer Center. Grape Seed. Page updated 10 February 2022. Read 2026-10-23.
- National Center for Complementary and Integrative Health (NIH). Grape Seed Extract. Page updated February 2025. Read 2026-10-23.
- The impact of grape seed extract treatment on blood pressure changes: a meta-analysis of 16 randomized controlled trials. Medicine (Baltimore), 2016. PMID 27537554. Abstract read through Europe PMC, 2026-10-23.
- Grape seed extract and flow-mediated dilation, blood pressure and heart rate: systematic review and meta-analysis. Pharmacological Research, 2022. PMID 34798267. Abstract read through Europe PMC, 2026-10-23.
- Effects of grape seed extract on dyslipidaemia: systematic review and dose-response meta-analysis of randomised controlled trials. British Journal of Nutrition, 2020. PMID 32138795. Abstract read through Europe PMC, 2026-10-23.
- GBIF Secretariat. GBIF species match: Vitis vinifera. Read 2026-10-23.