Eicosatrienoic acid (all cis-5,8,11) is a product of oleic acid through D5 and D6 desaturation and elongation1 and it is one of the few polyunsaturated fatty acids produced de novo by animals. It is found mostly in cartilage, umbilical cords, fetuses, infants, and low vascular tissues. Eicosatrienoic acid (all cis-5,8,11) accumulates in essential fatty acid deficient animals and this is likely what accounts for where it is found. It has been found to suppresses osteoblast, but not osteoclast, activity in some studies. This may help in preventing calcification of fetal cartilage and lead to new therapeutic treatments.2 Eicosatrienoic acid (all cis-5,8,11) also has anti-inflammatory effects by inhibiting leukotrienes and is an inhibitor of platelet aggregation.3