What is it used for?
Source of antioxidants/Provides antioxidants [Source note 2].
Source of antioxidants/Provides antioxidants that help fight/protect (cell) against/reduce (the oxidative effect of/the oxidative damage caused by/cell damage caused by) free radicals [Source note 3].
Helps to relieve symptoms related to non-complicated chronic venous insufficiency (CVI), such as sensation of swelling, heaviness and tingling of the legs [Source note 4].
Who does this guide cover?
Adults 18 years and older
How is it taken?
Oral
Which forms are covered?
this reference excludes foods or food-like dosage forms as indicated in the Compendium of references Guidance Document.
Quantities
Antioxidant
Methods of preparation: Standardized extracts (Dry extract)
Not to exceed 475 milligrams of grape seed extract, per day; standardized to 70-85% oligomeric proanthocyanidins (OPC) [Source note 5].
Relief of symptoms related to non-complicated CVI
Methods of preparation: Standardized extracts (Dry extract)
150 - 475 milligrams of grape seed extract, per day; standardized to 80-85% oligomeric proanthocyanidins (OPC) [Source note 6]
How is it used?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
How long is it used?
All products
Ask a healthcare professional for use beyond 3 months [Source note 7].
Relief of symptoms related to non-complicated CVI
Use for at least 1 month to see beneficial effects [Source note 8].
Warnings and precautions
All products
Ask a healthcare professional before use if you are pregnant or breastfeeding.
Relief of symptoms related to non-complicated CVI
Ask a healthcare professional if symptoms worsen.
When should it be avoided?
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Possible side effects
The reference does not require an additional label statement in this section. This does not establish an absence of risk.
Storage
Must be established in accordance with the requirements described in the applicable product regulations.
Preparation details
Ingredient identity, preparation requirements, and other details that define the scope of this guide.
Ingredients and preparations
| Proper name(s) | Common name(s) | Source information / Source material(s) | Source information / Part(s) | Source information |
|---|---|---|---|---|
| Grape seed extract | Grape seed extract | Vitis vinifera | Seed |
References: Proper name: Sano et al. 2007; Common name: Sano et al. 2007; Source information: USDA 2023, Sano et al. 2007, Henriet 1993.
Other ingredients
Must be chosen from the current source ingredient database and must meet the limitations outlined in the database.
Preparation and quality requirements
The finished product specifications must be established in accordance with the requirements described in the source authority source’s product quality guidance.
The active ingredient must comply with the requirements outlined in the source ingredient database.
Guide change history
Updates to this SupplementSafety.org guide.
Minor updates
Updated guide wording, organization, and source presentation. Added our editorial change history.
Initial release
Initial SupplementSafety.org guide prepared from source reference material.
Validation: Not yet completed. Editorial updates do not constitute clinical validation.
Sources
Source information
This guide organizes source material about uses, preparations, amounts, and precautions. Read the conditions alongside each statement; the information may apply only to particular preparations or populations.
The source document includes supporting references. We have not independently summarized or assessed every cited study for this guide.
- Source document version
- March 28, 2024
- Source captured
- Aug 15, 2026
- Editorial work
- Editorial preparation. Independent clinical review has not been recorded for this guide.
Full citations are available through the link above. Verification is required to open them; reading this guide does not require verification.
Taking a medication too?
Explore our supplement–medication interaction checker. Its coverage and review status are shown with the results; a missing finding does not establish that a combination is safe.