Sebum is made by sebaceous glands, which are microscopic glands located within your hair follicles. These glands produce an oily substance called sebum that helps to keep your skin moist and protected.
Sebum is produced through a process called holocrine secretion. The cells within the sebaceous gland accumulate lipids and eventually disintegrate, releasing the sebum into the hair follicle. This process takes about a week.
Sebaceous glands are found all over the body, but they are most concentrated on the face, scalp, and chest. They are particularly active during puberty, which can lead to an increase in oil production and acne.
