What is Sebum?

Getting Your Body's Sebum Production Under Control

A cross-section of human skin.
A cross-section of human skin.. BSIP/UIG/Getty Images

Sebum is a light yellow, oily substance secreted by the sebaceous glands that keep the skin and hair moisturized. Sebum is made up of triglycerides, free fatty acids, wax esters, squalene, cholesterol esters, and cholesterol. The oil on the surface of the skin isn't just made up of sebum, however. It also includes lipids from skin cells, sweat, and environmental matter.

The sebaceous glands produce sebum.

Sebaceous glands can be found almost everywhere on the body except the palms of the hands and the soles of the feet. There is a greater concentration of sebaceous glands on the middle of the back, the genital area and face - particularly the forehead and chin. Most sebaceous glands are connected to a hair follicle, although some open up directly to the surface of the skin, like the glands on the eyelids, the preputial glands and Fordyce spots on the genitals and upper lip.

Before sebum makes its way to the surface of the skin, it combines with cells in the process of being sloughed off inside the hair follicle. When the follicle fills up, sebum spreads over the surface of the skin, making it moisturized and healthy. When this process doesn't work correctly, it results in oily skin and hair, medically known as seborrhea. An excess of sebum, dead skin cells, and dirt trapped inside pores can also lead to acne.

Conversely, when not enough sebum is produced the skin becomes dry.

Trying to find the right balance of sebum production is frustrating, but sebum isn't the enemy. It's a naturally-occurring, necessary substance that:

  • Keeps the hair and skin healthy and moisturized.
  • Maintains the skin's flexibility.
  • Prevents the skin from losing water.
  • Acts as a barrier, protecting the skin from bacterial and fungal infections.

Factors That Affect Sebum Production

Sebum production is controlled by hormones; specifically, androgens like testosterone. During puberty, the sebaceous glands enlarge and the hormones become more active, thus producing more sebum. This is why acne is such a hallmark of adolescence. During puberty males produce up to 5 times more sebum than females. Sebum production starts to decrease by age 20 and continues to slow with age.

The amount of sebum your body produces can also be affected by certain diseases and medications, too. For example, disorders related to the pituitary and adrenal glands, the ovaries and the testicles can increase or decrease sebum production. Starvation reduces production, and Parkinson's disease increases it.

Certain medications like oral contraceptives, antiandrogens and vitamin A derivatives like isotretinoin are all known to reduce sebum productions. Others, like testosterone and progesterones, are known to increase sebum production.

How to Fix Dry Skin

If your body isn't producing enough sebum, your skin might be dry, red, flaky or itchy. Dry skin is exacerbated by using soaps that are too harsh for the skin and taking frequent, long, hot showers. Luckily dry skin is a relatively simple fix. After showering, pat the skin dry and apply a quality moisturizer.

Look for a moisturizer that contains ceramides, emollients, sorbitol, glycerin or humectants. Thicker, greasier moisturizers contain ingredients like petroleum jelly and mineral oil. They're definitely more effective, but they take a while to sink into the skin and they can clog pores.

How to Fix Oily Skin

If you have the opposite problem and your body is producing too much sebum, your hormones are probably to blame. Wash your face twice daily and use a gentle exfoliating scrub a few times a week. Look specifically for products that are oil-free.

You should always wash your face and remove any makeup before going to bed. Allowing that dirt, oil and makeup to stay stuck in your skin is just asking for trouble. If you wear makeup, be sure to keep your makeup brushes clean, too.

Sources:

http://www.dermnetnz.org/acne/sebum.html

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