epicatechin

Epicatechin is a natural flavanol, a type of flavonoid found in various plants. It is one of two stereoisomers of the flavanol catechin; the natural form occurs predominantly as (-)-epicatechin. Its chemical formula is C15H14O6.

Sources include cocoa and cocoa products, green and black tea, apples, grapes, and berries. In foods, epicatechin contributes to astringency and bitterness. It is also a monomeric unit of proanthocyanidins (condensed tannins), which are polymers of flavanol units.

Biological activities: Epicatechin has antioxidant properties in vitro and in vivo; it modulates signaling pathways related to endothelial function and inflammation. Some human studies have reported improvements in vascular function, blood pressure, and insulin sensitivity with epicatechin-containing foods or supplements, but results are inconsistent and not sufficient to establish disease-treatment claims.

Pharmacokinetics and metabolism: After ingestion, epicatechin is absorbed and rapidly metabolized to conjugated forms (glucuronides, sulfates) in the intestine and liver, with excretion mainly in urine. Bioavailability depends on food matrix and gut microbiota.

Safety: In usual dietary amounts, epicatechin is considered safe. High-dose supplements have not established efficacy and may carry risks or interact with medications; individuals with certain medical conditions or who are pregnant should consult a healthcare provider.