Supplement
Contains bioactive phytochemicals that may modulate stress, immune, and metabolic pathways.[1809,3456,3488, etc.]
Superscript reference numbers link to the Sources bibliography.
Composite Rating
Blends evidence depth, community direction, safety friction, and completeness.
Evidence Intensity
100/100
High depth from human/RCT/meta counts
Community Direction
0
Mixed / Neutral • confidence Minimal
Safety Friction
100/100
High signal from adverse/interaction markers
Data Completeness
100%
Studies 15 • mentions 2 • links 25
Not medical advice. This product is for educational and informational purposes only. It does not diagnose, treat, cure, or prevent any disease and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition.
FDA disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Results may vary. Not intended for use by pregnant or nursing women, individuals under 18, or those with known medical conditions without physician consultation.
If you are experiencing a medical emergency, call 911 or your local emergency number immediately.
Goal alignment: Stress Resilience, Mood, Immune Support, Longevity.[514,662,886, etc.]
Dose guide: Human-study daily dose: 3 mg-400 mg/day (higher-confidence extraction from PubMed abstracts)..[514,662,886, etc.]
Category
Botanical
Evidence Tier
HIGH
Daily Guide
Human-study daily dose: 3 mg-400 mg/day (higher-confidence extraction from PubMed abstracts).
Dosing Guide
Human-study daily dose: 3 mg-400 mg/day (higher-confidence extraction from PubMed abstracts).[,, etc.]
Clinical Depth
Humans: 138 • RCTs: 29 • Meta: 8
Cohort / Real-World
Cohort signals: 0
Safety Markers
Adverse signals: 156 • Interactions: 97
Freshness, trend, and study timeline for this item
Status
Trend
→ Stable evidence base
Depth
394 total studies · 4 recent
Timeline
Animal-only studies
636
Total indexed
394
In vitro / tissue
339
Safety adverse signals
156
Human studies
138
Interaction signals
97
Weighted direction score: 0 (Mixed / Neutral)
High when >=2 human meta-analyses, or >=5 human RCTs with substantial human literature volume.
Animal-only studies
636
Total indexed
394
In vitro / tissue
339
Safety adverse signals
156
Human studies
138
Interaction signals
97
Randomized trials
29
Meta-analyses
8
Distribution of evidence by study design strength
Evidence Strength: High
Composite of study volume, RCTs, and meta-analyses
PMID 34798267 • 2022 Jan
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
Open PubMedPMID 34107109 • 2021 Nov
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
Open PubMedPMID 31760860 • 2020 Mar
Benefit reports: 1
Adverse reports: 1
No-effect reports: 0
Mixed reports: 0
Unclear reports: 0
Signal confidence: 0.00
Benefits
Adverse
No Effect
Insufficient empirical signal for a directional adjustment.
Reddit evidence: 0 mentions (confidence 0.00).
Amazon signal: 0 products scanned (confidence 0.00).
GNC signal: 0 products scanned (confidence 0.00) [ERROR].
terminated
Search fetch failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=relevance&t=year&limit=12&q=%22grape%20seed%20extract%22%20(supplement%20OR%20dosage%20OR%20stack%20OR%20side%20effects%20OR%20review)%20(subreddit%3ASupplements%20OR%20subreddit%3ANootropics%20OR%20subreddit%3ABiohackers%20OR%20subreddit%3Alongevity%20OR%20subreddit%3ANutrition%20OR%20subreddit%3AHubermanLab%20OR%20subreddit%3ASleep%20OR%20subreddit%3AFitness%20OR%20subreddit%3Aketoscience%20OR%20subreddit%3AStackAdvice)
aggregate • unclear
Aggregate community signal: 2 directional mentions (benefit 1, adverse 1, no-effect 0, mixed 0).
Open mentionamazon
Amazon search for Grape Seed Extract
Rating: n/a | Reviews: n/a
Open productEvidence Sources
PUBMED • Humans + preclinical triage
Counts aggregated from automated literature sweep and tiering rules.
Outcome: Tier HIGH; humans 138, RCTs 29, meta-analyses 8.[1809,3456,3488, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 34798267 from Pharmacol Res.
See linked PubMed abstract for methods and outcomes.
Prevention of dental caries by grape seed extract supplementation: A systematic review.
Nutr Health
PMID 38141198 • 2024
Does the Grape Products Intake has an Effect on Body Weight in Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials.
Curr Drug Targets
Open PubMedPMID 31880030 • 2020 Feb
The effects of grape seed extract on glycemic control, serum lipoproteins, inflammation, and body weight: A systematic review and meta-analysis of randomized controlled trials.
Phytother Res
Open PubMedPMID 32921322 • 2021 Jun 14
The effect of grape products containing polyphenols on C-reactive protein levels: a systematic review and meta-analysis of randomised controlled trials.
Br J Nutr
Open PubMedPMID 38419408 • 2024 Jun
Grape seed extract supplementation in non-alcoholic fatty liver disease.
Int J Vitam Nutr Res
Open PubMedPMID 38755622 • 2024 May 16
The effects of grape seed extract supplementation on cardiovascular risk factors, liver enzymes and hepatic steatosis in patients with non-alcoholic fatty liver disease: a randomised, double-blind, placebo-controlled study.
BMC Complement Med Ther
Open PubMedPMID 37375586 • 2023 Jun 9
Low Dose Monacolin K Combined with Coenzyme Q10, Grape Seed, and Olive Leaf Extracts Lowers LDL Cholesterol in Patients with Mild Dyslipidemia: A Multicenter, Randomized Controlled Trial.
Nutrients
Open PubMedPMID 31942838 • 2022 Jan
Grape seed polyphenol extract and cognitive function in healthy young adults: a randomised, placebo-controlled, parallel-groups acute-on-chronic trial.
Nutr Neurosci
Open PubMedPMID 37832335 • 2023 Nov
Grape seed extract in combination with deferasirox ameliorates iron overload, oxidative stress, inflammation, and liver dysfunction in beta thalassemia children.
Complement Ther Clin Pract
Open PubMedPMID 33671310 • 2021 Feb 17
Grape Seed Extract Positively Modulates Blood Pressure and Perceived Stress: A Randomized, Double-Blind, Placebo-Controlled Study in Healthy Volunteers.
Nutrients
Open PubMedPMID 39612889 • 2025 Jan
Proanthocyanidins alleviate acute alcohol liver injury by inhibiting pyroptosis via inhibiting the ROS-MLKL-CTSB-NLRP3 pathway.
Phytomedicine
Open PubMedPMID 18045358 • 2007 Sep-Oct
Less-known botanical cosmeceuticals.
Dermatol Ther
Open PubMedPMID 34067538 • 2021 May 17
Efficacy of Bilberry and Grape Seed Extract Supplement Interventions to Improve Glucose and Cholesterol Metabolism and Blood Pressure in Different Populations-A Systematic Review of the Literature.
Nutrients
Open PubMedFallback search failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=comments&t=all&limit=16&q=%22grape%20seed%20extract%22%20(supplement%20OR%20capsule%20OR%20powder%20OR%20experience%20OR%20results%20OR%20side%20effects)
Broad search failed: Failed to fetch after retries: https://old.reddit.com/search.json?raw_json=1&sort=new&t=all&limit=16&q=grape%20seed%20extract
Use adverse/interactions PubMed signal counts for screening; perform clinician review before high-dose or multi-drug stack use.
Human-study daily dose signal: 3 mg-400 mg/day (confidence HIGH).
Extracted from 8 dosing mentions across 5 PubMed studies (mg/day).
Community Sources
PUBMED • 2021 • Human evidence curation set
PMID 34107109 from Int J Clin Pract.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2020 • Human evidence curation set
PMID 31760860 from Nutr Health.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 38141198 from Curr Drug Targets.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2020 • Human evidence curation set
PMID 31880030 from Phytother Res.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 32921322 from Br J Nutr.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 38419408 from Int J Vitam Nutr Res.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2024 • Human evidence curation set
PMID 38755622 from BMC Complement Med Ther.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 37375586 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2022 • Human evidence curation set
PMID 31942838 from Nutr Neurosci.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2023 • Human evidence curation set
PMID 37832335 from Complement Ther Clin Pract.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 33671310 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2025 • Human evidence curation set
PMID 39612889 from Phytomedicine.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2007 • Human evidence curation set
PMID 18045358 from Dermatol Ther.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open sourcePUBMED • 2021 • Human evidence curation set
PMID 34067538 from Nutrients.
Outcome: See linked PubMed abstract for methods and outcomes.[1809,3456,3488, etc.]
Open source