Omega-9 fatty acids (ω−9 fatty acids or n−9 fatty acids) are a family of unsaturated fatty acids which have in common a final carbon–carbon double bond in the omega−9 position; that is, the ninth bond from the methyl end of the fatty acid.

Unlike omega-3 fatty acids and omega-6 fatty acids, omega−9 fatty acids are not classed as essential fatty acids (EFA). This is both because they can be created by the human body from unsaturated fat, and are therefore not essential in the diet, and because the lack of an omega−6 double bond keeps them from participating in the reactions that form the eicosanoids.


Some omega−9 fatty acids are common components of animal fat and vegetable oil. Two omega−9 fatty acids important in industry are:

Under severe conditions of EFA deprivation, mammals will elongate and desaturate oleic acid to make Mead acid, (20:3, n−9).[1] This has been documented to a lesser extent in one study following vegetarians and semi-vegetarians who followed diets without substantial sources of EFA.[2]

Omega−9 fatty acids
Common name Lipid name Chemical name
hypogeic acid 16:1 (n−9) (Z)-hexadec-7-enoic acid
oleic acid 18:1 (n−9) (Z)-octadec-9-enoic acid
elaidic acid 18:1 (n−9) (E)-octadec-9-enoic acid
gondoic acid 20:1 (n−9) (Z)-eicos-11-enoic acid
Mead acid 20:3 (n−9) (5Z,8Z,11Z)-eicosa-5,8,11-trienoic acid
erucic acid 22:1 (n−9) (Z)-docos-13-enoic acid
nervonic acid 24:1 (n−9) (Z)-tetracos-15-enoic acid
ximenic acid 26:1 (n−9)

See also


  1. ^ Lipomics. "Mead acid". Archived from the original on March 19, 2006. Retrieved February 14, 2006.
  2. ^ Phinney SD, Odin RS, Johnson SB, Holman RT (March 1990). "Reduced arachidonate in serum phospholipids and cholesteryl esters associated with vegetarian diets in humans". Am. J. Clin. Nutr. 51 (3): 385–92. doi:10.1093/ajcn/51.3.385. PMID 2106775.