Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Lanolin is a yellow waxy substance secreted by the sebaceous glands of wool-bearing animals. Most lanolin used by humans comes from domestic sheep. Lanolin is also frequently, but incorrectly, referred to as Wool Fat by many of the world s pharmacopoeias even though it has been known for more than 150 years that lanolin is devoid of glycerides and is in fact a wax, not a fat. Lanolin's waterproofing property aids sheep in shedding water from their coats.