At levels found in common foods, such as in red wine and grapes, trans-resveratrol is probably safe, according to WebMD. The effects of trans-resveratrol taken at higher dosages, such as in supplements, are not known, but may increase the risk of bleeding if used with blood thinners or anti-inflammatory medications.
Resveratrol is a compound produced by plants that is found in many common foods, such as blueberries, grapes, and peanuts, says Harvard Health. In the 1990s, researchers suggested that the abundance of resveratrol in red wine might be the source of red wine's beneficial effects for the cardiovascular system. Since that time, researchers have suggested many other possible beneficial effects of resveratrol. These include possible reduced chances of cancer, Alzheimer's disease and dementia.
Some people take resveratrol to treat hardening of the arteries, to reduce harmful cholesterol levels and to prevent cancer, says WebMD. These benefits have not been scientifically confirmed. Moreover, the safety of resveratrol at higher dosages has also not been scientifically confirmed.
Most studies of resveratrol have examined its effects in fruit flies and other nonhuman organisms. These studies have examined the effects of dosages that are significantly higher than those usually found in supplements. Few studies have examined the effects of resveratrol on humans,says Harvard Health.