Anhydrous lanolin or reﬁned wool wax is a complex natural substance, designed by nature to protect and soften both skin and wool ﬁbres. Chemically it is a wax, a complex mixture of long chain esters and fatty acids with high molecular weight alcohols. 90-95 % of lanolin are esters and 5 – 10 % are free alcohols with small quantities of free fatty acids and hydrocarbons. Anhydrous lanolin is essentially a water-free wool wax. Wool wax is a much more complex matrix than for example vegetable oils, with a molecular mass distribution spanning 1002000 Da. More than 170 different fatty acids and more than 70 alcohols of high molecular weight have been identified in lanolin. Free fatty acids range from C9 to C33, in the “normal”, “iso” and ”ante-iso” types. The alcoholic fraction contains sterols, triterpene alcohols, aliphatic alcohols, mono-alcohols, diols and polyols. Approximately 35 % of the alcoholic fraction is cholesterol.