Squalene is a natural 30-carbon organic compound originally obtained for commercial purposes primarily from shark liver oil (hence its name), although plant sources (primarily vegetable oils) are now used as well, including amaranth seed, rice bran, wheat germ, and olives. It is also found in high concentrations in the stomach oil of birds in the order Procellariiformes. All plants and animals produce squalene as a biochemical intermediate, including humans.