Grape Seed Extract

© Steven Foster

This fact sheet provides basic information about grape seed extract—

common names, what the science says, potential side effects and 

cautions, and resources for more information.

Common Name—grape seed extract

Latin Name—Vitis vinifera

The leaves and fruit of the grape have been used medicinally since 

ancient Greece. Today, grape seed extract is used as a folk or traditional 

remedy for conditions related to the heart and blood vessels, such as 

atherosclerosis (hardening of the arteries), high blood pressure, high 

cholesterol, and poor circulation; complications related to diabetes, 

such as nerve and eye damage; vision problems, such as macular 

degeneration (which can cause blindness); swelling after an injury or 

surgery; cancer prevention; and wound healing.

The grape seeds used to produce grape seed extract are generally 

obtained from wine manufacturers. Grape seed extract is available in 

capsule and tablet forms.

What the Science Says 

• Studies have found that some compounds in grape seed extract may 

be effective in relieving symptoms of chronic venous insufficiency 

(when veins have problems sending blood from the legs back to the 

heart) and reducing edema (swelling) after an injury or surgery.

• Small randomized trials have found beneficial effects of grape seed 

extract for diabetic retinopathy (an eye problem caused by diabetes) 

and for vascular fragility (weakness in small blood vessels). Larger 

trials are needed to confirm these findings.

• Grape seed extract contains antioxidants, which help prevent cell 

damage caused by free radicals (highly reactive molecules that can 

damage cell function). Preliminary studies have shown some 

beneficial antioxidant effects; however, more research is needed.

• A study funded by the National Cancer Institute (NCI) found that 

grape seed extract did not reduce the hardening of breast tissue 

that can occur after radiation therapy for breast cancer.

• NCI is also funding studies to evaluate whether grape seed extract is 

effective in preventing breast cancer in postmenopausal women 

and prostate cancer.
• NCCAM is studying whether the action of grape seed extract and its components may 

benefit the heart or help prevent cognitive decline, Alzheimer’s disease, and other brain 

disorders. Another study is investigating the effects of grape seed extract on colon cancer.

Side Effects and Cautions 

• Grape seed extract is generally well tolerated when taken by mouth. It has been used safely 

for up to 8 weeks in clinical trials.

• Side effects that have been reported include a dry, itchy scalp; dizziness; headache; high 

blood pressure; hives; indigestion; and nausea.

• Interactions between grape seed extract and medicines or other supplements have not 

been carefully studied.

• Tell all your health care providers about any complementary health practices you use. Give 

them a full picture of what you do to manage your health. This will help ensure 

coordinated and safe care. For tips about talking with your health care providers about 

complementary and alternative medicine, see NCCAM’s Time to Talk campaign at 

nccam.nih.gov/timetotalk/. 

Sources

Brooker S, Martin S, Pearson A, et al. Double-blind, placebo-controlled, randomised phase II trial of IH636 grape seed 

proanthocyanidin extract (GSPE) in patients with radiation-induced breast induration. Radiotherapy and Oncology.

2006;79(1):45-51.

Clouatre DL, Kandaswami C. Grape seed extract. In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary 

Supplements. New York, NY: Marcel Dekker; 2005:309-325.

Grape. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on June 25, 2009.

Grape seed (Vitis vinifera, Vitis coignetiae). Natural Standard Database Web site. Accessed at www.naturalstandard.com

on June 25, 2009.

For More Information

Visit the NCCAM Web site at nccam.nih.gov and view Using Dietary Supplements Wisely

(nccam.nih.gov/health/supplements/wiseuse.htm).

NCCAM Clearinghouse

Toll-free in the U.S.: 1-888-644-6226

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615

E-mail: info@nccam.nih.gov

PubMed®

Web site: www.ncbi.nlm.nih.gov/sites/entrez

NIH Office of Dietary Supplements

Web site: www.ods.od.nih.gov

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCAM has provided this material for your information. It is not intended to substitute for the medical expertise and 

advice of your primary health care provider. We encourage you to discuss any decisions about treatment or care with 

your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCAM.

National Institutes of Health

♦♦♦

U.S. Department of Health and Human Services

D370

Created March 2007

Updated April 2012