Lanolin is a yellow fat obtained from sheep's wool. It is used as an emollient, cosmetic, and pharmaceutic aid. The US federal code of regulations states that lanolin in the concentration range of 12-50% may be included in over the counter skin ointments. Lanolin is the purified, secreted product of the sheep sebaceous glands. Lanolin primarily consists of long-chain waxy esters, or sterol esters, that lack glycerides. For this reason, it is also called wool wax or wool grease. Lanolin is used in the protection, treatment, and cosmetic enhancement of human skin. Its hydrophobic properties can help protect skin against infections or skin irritation, as it helps seal in moisture that is already present in the skin. Lanolin is used as an active ingredient in over the counter topical products such as ointments, lubricants, lotions and facial cosmetics. Lanolin is also frequently used in protective baby skin treatment and for sore nipples in breastfeeding mothers,.