Grape Seed Extract 

This fact sheet provides basic information about grape seed extract—uses, 

potential side effects, and resources for more information. The grape seeds 

used to produce grape seed extract are generally obtained from wine 

manufacturers. The leaves and fruit of the grape have been used 

medicinally since ancient Greece. 

Common Name—grape seed extract 

Latin Name—Vitis vinifera 

What It Is Used For 

•	 Grape seed extract is used for conditions related to the heart and blood 

vessels, such as atherosclerosis (hardening of the arteries), high blood 

pressure, high cholesterol, and poor circulation. 

•	 Other reasons for the use of grape seed extract include complications related 

to diabetes, such as nerve and eye damage; vision problems, such as 

macular degeneration (which can cause blindness); and swelling after an 

injury or surgery. 

•	 Grape seed extract is also used for cancer prevention and wound healing. 

How It Is Used 

Grape seed extract is prepared from the seed of grapes. It is available in capsule 

and tablet forms. 

What the Science Says 

•	 Laboratory studies have shown that grape seed contains antioxidants— 

substances that prevent cell damage caused by free radicals, which are 

highly reactive molecules that can damage cell function. However, it is still 

unclear how grape seed might affect human health. 

•	 Grape seed extract has shown some beneficial antioxidant effects in 

preliminary clinical trials. However, few trials have looked at specific 

diseases or conditions, and little scientific evidence is available. 

•	 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 evaluating whether grape seed extract is 

effective in preventing breast and prostate cancers. 

•	 NCCAM is studying whether the action of grape seed extract and its 

components may benefit the heart or have protective effects in the brain. 
 

 

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 most often include headache; a dry, itchy scalp; 

dizziness; and nausea. 

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

been carefully studied. 

•	 Tell your health care providers about any complementary and alternative practices you 

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

coordinated and safe care. 

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 http://www.naturaldatabase.com on 

March 13, 2007. 

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

http://www.naturalstandard.com on March 13, 2007. 

For More Information 

Visit the NCCAM Web site at nccam.nih.gov and view: 

•	 What’s in the Bottle? An Introduction to Dietary Supplements at nccam.nih.gov/health/bottle/ 

•	 Herbal Supplements: Consider Safety, Too at nccam.nih.gov/health/supplement-safety/ 

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 

CAM on PubMed 

Web site: nccam.nih.gov/camonpubmed/ 

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 May 2008 

*D370*