Trans-Resveratrol 200 with Resvinol from Doctor's Best delivers 200 mg of tran-resveratrol in each serving. This formula features ResVinol-25, a proprietary extract that features concentrated levels of polyphenols and trans-resveratrol from the red wine matrix and the root of the Japanese knotweed (Polygonum cuspidatum) plant. Research suggests trans-resveratrol has valuable biological activity. This product is extensively tested for heavy metals, bacterial and fungi contaminants and pesticides to verify purity and compliance with acceptable standards.