Palmitoleic acid (hexadec-9-enoic acid; 9-trans-Hexadecenoic acid), the trans isomer of palmitoleic acid, is an omega-7 monounsaturated fatty acid with the formula CH5CH=CH(CH2)7COOH that is a common constituent of the glycerides of human adipose tissue. It is present in all tissues but, in general, found in higher concentrations in the liver. It is biosynthesized from palmitic acid by the action of the enzyme Stearoyl-CoA desaturase-1.