Epicatechin is an antioxidant flavonoid, occurring especially in woody plants as both (+)-catechin and (-)-epicatechin (cis) forms. Epicatechin is present in many plants. High quantities can be found in cocoa, tea and grapes. Pure epicatechin is an odorless white powder. Epicatechin is a flavonol belonging to the group of flavonoids. Epicatechin is a strong antioxidant, has insulin mimic action and improves heart health.

Studies show that epicatechin and other flavonoids exert a protective role on osmotic fragility of cells, similar to that of insulin. The mechanism of action of epicatechin is different to that of insulin and remains speculative. In diabetic red blood cells epicatechin causes an increase in acetylcholinesterase activity. This activity is significantly lower in type 2 diabetic patients.

Epicatechin reduces lipid peroxidation and inhibits platelet aggregation. Epicatechin cause blood vessel dilation by regulating nitric oxide, a molecule secreted by the blood vessel endothelium to signal surrounding muscle to relax.