Grape seed extracts have a very high safety profile and can be successfully supplemented even for a long time. Studies have proven that it has antihypertensive properties, which is why it is often recommended to people who, due to genetic predisposition or unhygienic lifestyle, are at risk of hypertension.

Although the extract itself is safe, it may interact negatively with certain medications – including the interference with blood thinners and alteration of the metabolism of some antibiotics.

Some studies suggest that polyphenol-rich products may hinder iron absorption. For this reason, they should be taken in a time interval from meals containing iron-rich products (e.g. meat, offal).