- Does resveratrol help? There is some preliminary evidence that resveratrol supplements may be helpful for age-related macular degeneration. Evidence for other popularly promoted uses, such as cardiovascular health and lowering cholesterol, improving insulin sensitivity in diabetes, improving memory, and "life-extension" is quite limited, and in some cases, contradictory (see What It Does).
- Which form of resveratrol is best? Resveratrol is a plant chemical found in red grape skins and grape seeds, purple grape juice and red wine, but most resveratrol in supplements comes from the Japanese knotweed plant (Fallopia japonica or Polygonum cuspidatum). Resveratrol exists in either the cis- or trans- form, but trans-resveratrol is found most abundantly in nature and is the most-researched form (see What It Is).
- How much resveratrol is actually in supplements? All of the products tested in this review were found to contain the amounts of resveratrol claimed on their labels, which ranged from about 106 to 618 mg per serving (see What CL Found.) This is an improvement over 2016 when CL found that a "resveratrol complex" in a product was 11.8% resveratrol.
- Which resveratrol supplement is best? Among the resveratrol products that were Approved for their quality in our tests, the cost to obtain 100 mg of trans-resveratrol ranged from just 5 cents to $1.40. We selected two products that provided high-quality resveratrol at relatively low cost as our Top Picks.
- What is the right dose of resveratrol? Although there is no established safe and effective dose for resveratrol, a typical dose of approximately 150 mg per day may have activity in people, although higher doses are also used (see ConsumerTips).
- Is resveratrol safe? Resveratrol should not be taken by women with estrogen-sensitive conditions, nor by children, or women who are pregnant. People taking blood thinners are strongly advised to consult a physician before taking resveratrol because of potential drug interactions (see Concerns and Cautions) for more information.