Squalene is an organic compound. It is a triterpene with the formula CH. It is a colourless oil, although impure samples appear yellow. It was originally obtained from shark liver oil (hence its name, as Squalus is a genus of sharks). An estimated 12% of bodily squalene in humans is found in sebum. Squalene has a role in topical skin lubrication and protection.
Most plants, fungi, and animals produce squalene as biochemical precursor in sterol biosynthesis, including cholesterol and steroid hormones in the human body. It is also an intermediate in the biosynthesis of hopanoids in many bacteria.
Squalene is an important ingredient in some vaccine adjuvants: The Novartis and GlaxoSmithKline adjuvants are called MF59 and AS03, respectively.