Lip skin is much thinner than the skin on the rest of your face. It has fewer melanocytes (the cells that produce melanin, the pigment that give skin its color and protects from UV radiation) and so lips appear red. Lip skin doesn’t have any sweat or sebaceous glands. These glands play a key role in maintaining moisture levels and so the fact that there aren’t any in lip skin makes our lips particularly prone to drying out.