Lanolin (from
Latin lana, ‘wool’, and
oleum, ‘oil’), also called
wool wax or
wool grease, is a wax secreted by the
sebaceous glands of
wool-bearing animals. Lanolin used by humans comes from
domestic sheep breeds that are raised specifically for their wool. Historically, many
pharmacopoeias have referred to lanolin as wool fat (
adeps lanae); however, as lanolin lacks
glycerides (glycerol esters), it is not a true fat. Lanolin primarily consists of
sterol esters instead. Lanolin's waterproofing property aids sheep in shedding water from their coats. Certain breeds of sheep produce large amounts of lanolin. There is an inverse correlation between fiber diameter and wool wax content.