Found in fish liver oils, yeast lipids and many vegetable oils, e.g. palm oil, cottonseed oil, rapeseed oil A natural raw material found in human sebum (5%) and in shark-liver oil. An unsaturated aliphatic hydrocarbon (carotenoid) with six unconjugated double bonds. (Hawley's Condensed Chemical Reference) Biological Source: Found in fish liver oils, yeast lipids and many vegetable oils, e.g. palm oil, cottonseed oil, rapeseed oil. Volatile component of scent material from Saguinus oedipus (cotton-top tamarin monkey) and Saguinus fuscicollis (saddle-back tamarin monkey). Component of adult human sebum principally responsible for the fixing of fingerprints (ChemNetBase) Squalene is a natural organic compound originally obtained for commercial purposes primarily from shark liver oil, though there are botanical sources as well, including rice bran, wheat germ, and olives. All higher organisms produce squalene, including humans. It is a hydrocarbon and a triterpene. -- Wikipedia; Squalene is a low density compound often stored in the bodies of cartilaginous fish such as sharks, which lack a swim bladder and must therefore reduce their body density with fats and oils. Squalene, which is stored mainly in the shark's liver, is lighter than water with a specific gravity of 0.855. Recently it has become a trend for sharks to be hunted to process their livers for the purpose of making squalene health capsules. Environmental and other concerns over shark hunting have motivated its extraction from vegetable sources instead.; Squalene is a low density compound often stored in the bodies of cartilaginous fishes such as sharks, which lack a swim bladder and must therefore reduce their body density with fats and oils. Squalene, which is stored mainly in the shark's liver, is lighter than water with a specific gravity of 0.855. -- Wikipedia Uses: Bactericide. Intermediate in the manufacture of pharmaceuticals, rubber chemicals and coloring materials (Physical Constants of Chemical Substances); Squalene is a natural organic compound originally obtained for commercial purposes primarily from shark liver oil, though botanic sources (primarily vegetable oils) are used as well, including amaranth seed, rice bran, wheat germ, and olives. All higher organisms produce squalene, including humans. It is a hydrocarbon and a triterpene. Squalene is a natural and vital part of the synthesis of cholesterol, steroid hormones, and vitamin D in the human body; Squalene is the biochemical precursor to the whole family of steroids. Oxidation (via squalene monooxygenase) of one of the terminal double bonds of squalene yields 2,3-squalene oxide, which undergoes enzyme-catalyzed cyclization to afford lanosterol, which is then elaborated into cholesterol and other steroids.; Squalene is the biochemical precursor to the whole family of steroids. Oxidation of one of the terminal double bonds of squalene yields 2,3-squalene oxide which undergoes enzyme-catalyzed cyclization to afford lanosterol, which is then elaborated into cholesterol and other steroids. -- Wikipedia; Vaccines originally contained a weakened or killed pathogen. Newer vaccines contain only pure proteins or protein fragments, which makes them safer. But the missing parts of the pathogen are part of the immune response. Adjuvants are used to replace those parts, and squalene is one of those adjuvants.