The side effects of resveratrol possibly include slowed blood clotting and hormonal effects similar to estrogen. In general, it is safe in the amounts located in foods or in common supplements, although pregnant women should not drink wine in order to access resveratrol, as stated by WebMD.
Resveratrol is a chemical that appears in red grape skins, purple grape juice, red wine, mulberries and peanuts. People take it to treat atherosclerosis (hardened arteries), prevent cancer, boost levels of good HDL cholesterol, lower levels of bad LDL cholesterol and to treat acne, among other conditions. Research indicates that resveratrol may expand blood vessels and reduce cellular activity related to clotting, notes WebMD.
While scientific studies about resveratrol are ongoing as of 2015, there has not yet been enough evidence to demonstrate that resveratrol helps with any of these conditions. However, researchers have found that resveratrol is generally safe in food amounts and in supplement form up to 250 milligrams per day. Resveratrol creams that are used to treat acne are also likely to be safe. However, people who have bleeding disorders should avoid it, as it may slow clotting in blood and could elevate bleeding risk. The fact that resveratrol can resemble estrogen in the body means that people who have hormone-sensitive conditions, such as uterine fibroids, endometriosis or several forms of cancer, should avoid resveratrol, according to WebMD.