Grape Seed Extract: Fast Facts, Dosage, and Herb Blends
Once a by-product of the industrial wine and juice-making process, studies on grape seed extract (GSE) reveal promising health benefits from collecting the leftover seeds.
Grapes, depending on the botanist1 you ask, are technically a berry and fruit. They’re the star ingredient in jams, raisins, fruit baskets, and wines from all over the world, resulting in 69 million metric tons2 per production year.
Whether you’re a beginner or an experienced herbalist, you might be wondering if grape seed extract really works. A 2020 review of studies3 indicates that grape seeds contain bioactive compounds that positively affect inflammation, heart health, cancer, autoimmune disorders, and some bacterial infections.
Grape seed extract fast facts:
- Family: Vitaceae
- Genus: Vitis
- Taste: Bitter
- Popular varieties:Vitis vinifera, Vitis amurensis, Vitis labrusca
- Forms: Tinctures, capsules, powders, liquid concentrate
- Therapeutic compounds in seeds: Polyphenols (proanthocyanidins), phenolic acids, fatty acids, flavonols (catechins)
This article discusses grape seed uses in traditional herbal medicine, clinical research findings, and dosage recommendations, followed by a list of antioxidant plant blends to add to your diet.
Traditional and Modern Uses
Grapes date back to Greek philosophy and prehistoric times4. The most popular species, the common grapevine (Vitis vinifera), is native to southern Europe and western Asia. Today, it grows in temperate regions worldwide.
According to Andrew Chevallier, author of The Encyclopedia of Herbal Medicine5, grape seeds are only a part of the vine’s medicinal value. Grapes leaves have been used:
- As an astringent/anti-inflammatory
- As an infusion for diarrhea, heavy menstrual/uterine bleeding
- As a wash for mouth ulcers or vaginal discharge
- In combination with the fruit of grapes for varicose veins/hemorrhoids
Grapes are a staple in Ayurvedic medicine, particularly for their antibacterial6 and adaptogenic7 properties.
Grape seed extract vs. resveratrol
Similarly, emerging scientific data8 argues that different grape parts, such as grape seeds and resveratrol from the skins, have synergistic interactions and work better for disease prevention when combined.
In part due to their potent antioxidant content, clinical research suggests that grape seeds may be beneficial for:
A 2016 review of studies9 found that GSE beneficially impacts high blood pressure (hypertension). The effect was more obvious for people with obesity, young test subjects, and those with metabolic disorders. While the biological mechanism behind grape seed extract for blood pressure regulation remains speculative, researchers believe a strong correlation exists between the antioxidants in grape seeds and reduced free radical damage from oxidative stress.
GSE may also benefit blood flow stagnation and leg swelling from sitting, based on findings from a small 2012 clinical trial10 in healthy women.
Estrogen and testosterone
The research11 on GSE for breast cancer-related estrogen suppression is controversial and inconclusive. However, a study12 featuring 91 women with postmenopausal symptoms assessed the benefits of a 100 mg to 200 mg GSE dosage per day. After eight weeks, hot flashes and insomnia scores decreased in the high-dose group, while blood pressure decreased in both groups.
For testosterone, preliminary research13 in animals suggests that GSE may offset oxidative stress and testicular damage from Cisplatin, a chemotherapy medication used for different kinds of cancer. The results indicate the possibility of upregulated testosterone expression from GSE.
High cholesterol is a risk factor for heart disease, stroke, hardened arteries, and diabetes. An older study14 with 61 healthy subjects found a positive correlation between 200 mg to 400 mg GSE and lower LDL (“bad” cholesterol). Larger, more targeted studies on patients with high cholesterol are warranted.
Skin, wounds, and bacteria
Compared to a placebo group, test subjects who applied a grape seed extract 2% cream healed more quickly after skin tag and mole removal in a small 2015 study15. Claims that GSE improves skin appearance may not be entirely false, based on another study16 with topical GSE. The results conclude that cosmetic grape formulations may improve acne, signs of aging, and discoloration.
Additional preliminary research indicates antimicrobial benefits for:
- Yeast infection17
- Foodborne bacteria (E.coli)18
- Antibiotic-resistant staph infection19
Many animal studies20 have examined the benefits of GSE for gut disturbances tied to overactive gut microflora and inflammation. The current findings show promise for future studies with GSE for human GI issues, such as inflammatory bowel disease.
As a free radical scavenger, GSE may have anticancer effects based on multiple test tube studies21 with breast, bladder, and colorectal cells. Although the effects aren’t fully understood, researchers attribute cancer cell inhibition to the antioxidant content of grape seeds.
Read next: The Essential Guide to Antioxidants
Dosing and Side Effects
The studies listed above included GSE extract dosages in the 100 mg to 800 mg range. Grape seeds generally have a low side effect profile. A documented case of recurrent nausea, diarrhea, vomiting, and weakness from GSE was found in 201622, but the report emphasizes the scarcity of adverse health effects of GSE in scientific literature.
People with circulatory diseases taking prescribed medication should ask a healthcare provider about possible interactions. As with most supplements, people who are pregnant or breastfeeding may choose to avoid GSE.
Researchers23 are starting to formulate scientific models to study herbs in Traditional Chinese Medicine (TCM) and clinically understand plant synergy (two or more substances that produce a therapeutic, combined effect).
If you believe the more herbs the merrier, Purpose+ is an Ayurvedic and TCM-inspired powder with 100 mg grape seed extract, 200 mg schisandara fruit, 100 mg amla, and more.
Grape seeds come from the discarded grape extraction process, usually red wine grapes. You can supplement with grape seed extract at any time during the day, so long as you follow a consistent dosing routine.
The antioxidant profile comes from proanthocyanidins and other bioactive compounds in grape seeds. People supplement with GSE for all kinds of health issues, perhaps more so for its circulatory and antibacterial benefits.
5 Chevallier, A. (2016). The Encyclopedia of Herbal Medicine. (3rd ed.). Penguin Random House.