Arachidonic acid is a polyunsaturated fatty acid with four cis double bonds, which are the sources of its flexibility and give it the capacity to react with molecular oxygen. Arachidonic acid is an omega-6 fatty acid. It is one of the essential fatty acids that our body cannot manufacture.

Arachidonic acid is present in the membrane of the body's cells, and is a precursor in the production of eicosanoids: the prostaglandins, thromboxanes, prostacyclin and the leukotrienes.