What is sebum?

Sebum is an oily substance produced by sebaceous glands in the skin. It plays a crucial role in maintaining the health of the epidermis, which is the outermost layer of skin. The oiliness of sebum provides a protective barrier, helping to prevent the skin from drying out and becoming susceptible to irritants and infections. This natural oil also lubricates both the skin and hair, giving them a smooth appearance and preventing breakage or brittleness.

The other options describe components or products related to skin health or nail care but do not accurately define sebum. Understanding the role of sebum is essential for recognizing its importance in skincare and overall skin health.