Eicosapentaenoic acid

Eicosapentaenoic acid (EPA or also icosapentaenoic acid) is an omega-3 fatty acid. In physiological literature, it is given the name 20:5(n-3). It also has the trivial name timnodonic acid. In chemical structure, EPA is a carboxylic acid with a 20-carbon chain and five cis double bonds; the first double bond is located at the third carbon from the omega end.


 * EPA and its metabolites act in the body largely by their interactions with the metabolites of arachidonic acid; see Essential fatty acid interactions for detail.

EPA is a polyunsaturated fatty acid that acts as a precursor for prostaglandin-3 (which inhibits platelet aggregation), thromboxane-3, and leukotriene-5 groups (all eicosanoids).

Clinical significance
The US National Institute of Health's MedlinePlus lists a large number of conditions in which EPA (alone or in concert with other ω-3 sources) is known or thought to be effective. Most of these involve its ability to lower inflammation.

Among omega-3 fatty acids, in particular EPA is thought to possess beneficial potential in mental conditions, such as schizophrenia. Several studies report an additional reduction in scores on symptom scales used to assess the severity of symptoms, when additional EPA is taken.

EPA has inhibitory effect on CYP2C9 and CYP2C19 hepatic enzymes. At high dose, it may also inhibit the activity of CYP2D6 and CYP3A4, important enzymes involved in drug metabolism.