Grape extract concentrates polyphenols like proanthocyanidins and resveratrol from grape seeds or skins. Standardized active compounds make it far more potent than whole grapes.
People take it to help circulation and keep blood vessels flexible. It also shields skin from oxidative stress and supports the immune system and healthy aging. Capsules or tablets are the usual form, taken with meals to boost absorption. Doses depend on concentration, so stick to the label directions.
Caution: Grape extract can thin the blood mildly. Check with a doctor if you take anticoagulants such as warfarin or aspirin. Stop using it at least two weeks before any surgery. Pregnant or breastfeeding women should get professional advice before use.