Lanolin is a common ingredient found in lip balms, shampoos, lotions, and cosmetics. It comes from excreted sheep sebum and it's found in their wool. It is then collected, neutralized, filtered, bleached, and deodorized into a waxy consistency with a yellowish color. While it can be extremely nourishing, soothing, and softening, lanolin has also been known to cause allergic reactions in humans.
Sheep are treated with pesticides to prevent disease and bugs. (Poor sheep!) If the pesticides aren't properly removed from the lanolin, it can lead to redness, inflammation, itchiness, and blisters. Additionally, over time, lanolin often leaves a greasy residue in fine hair.
If you are going to use lanolin-enhanced products, medical-grade lanolin is hypoallergenic. If you aren't sure about the quality of the lanolin, inquire about the chemical removal process. Lastly, if you have highly sensitive skin or an allergy to wool, stick with products that you know are lanolin free.