What Everyone Ought to Know About Sebum, How to Care for Oily Skin.

By Dr. Deborah Lee

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Sebum is oil! Yes, it’s that oily substance produced naturally by your skin every day. Your skin needs sebum to stay strong, healthy, and supple.

Love it or hate it, natural skin oil –  sebum –  is an essential part of your skin health. Without it, your skin would shrivel and die. Have you ever thought about this? Without sebum, seriously – you just wouldn’t exist! 

However, so many women are totally exasperated by their oily skin. This is a big issue for women – for example, there are almost 10,000 products on Amazon, listed as products for oily skin.

You may be thinking – What exactly is oily skin? – What factors make it better or worse? – How do I know if I have it? – What can I do about it?  

Read on and find out the answers…

/ Six Key-Steps For A Good Skin Care Routine.

woman with oily skin

What is oily skin?

The medical definition –  Sebum – is the correct term for the oil made naturally by your skin.

  • Normal skin – Sebum production 1mg/10cm2 every 3 hours
  • Oily skin  – Sebum production 1.5mg/10cm2 every 3 hours
  • Dry skin –  Sebum production 0.5mg//10cm2 every 3 hours 

If sebum is so important, let’s take a closer look. What’s in it,  and what does it do for your skin?

What is sebum?

Sebum is made in the sebaceous glands found in the skin all over your body. The sebaceous glands open into the base of the hair follicle, and sebum is continuously deposited from there, onto the skin surface.

Sebum contains squalene (12%), wax esters (26%), triglycerides and free fatty acids (57.5%)  and cholesterol (4.5%). 

  • Squalene is a hydrocarbon which is the precursor of cholesterol. It is concentrated within sebum secreting cells – called sebocytes which are situated within the sebaceous gland. It is a natural skin moisturiser.  Squalene production declines naturally with age. Squalene also has an important role in protecting the skin from U/V light.
  • Wax esters make up one-quarter of sebum. They have to date, received little medical interest. Wax esters are found in the waxy leaves of plants, or for example on bird feathers or animal coats. These seal in heat and moisture and prevent water evaporation. They also have a self-cleaning function to repel any invading substances and organisms. 
  • Fatty acids  – Sapienic acid is the most common fatty acid found in sebum, and is only found on humans, and nowhere else in the body. Its function is unclear, but it may have an antibacterial role in acne. Other triglycerides in sebum include and triacylglycerols (TAG), diacylglycerols (DAG).
  • Cholesterol is found in sebum. Medical studies have shown that restricting calories reduces the cholesterol output in sebum. A high-fat diet, however, increases sebum output. One theory is that cholesterol secretion in sebum is means of the body controlling cholesterol metabolism and homeostasis.

In summary, sebum protects the skin from the sun, helps your body retain internal moisture and repel external wate from the skin surface, and has a self- cleaning and an antibacterial action on the skin.

What causes excess sebum?

Here’s a list of factors associated with increased sebum production

  • Ageing – sebum production increases after puberty, and declines after menopause.
  • Being a man – it seems to be related to higher testosterone levels.
  • Women – sebum levels increase around the time of ovulation.
  • Time of year – more sebum is produced in spring and summer.
  • Climate – more sebum is produced in humid climates.
  • African Americans – tend to have larger pores sizes, and hence produce more sebum.
  • Medical conditions – Some are associated with increased testosterone levels – Polycystic ovarian syndrome (PCOS), and rare conditions e.g. congenital adrenal hyperplasia.


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How do you know you have oily skin?

Does your skin look –

  • Is it greasy or shiny?
  • Does it look thickened?
  • Are there large pores?
  • Can you see blackheads?
  • Do you get little pus-filled spots – pimples?

If so, you have greasy skin.

Combination skin

Some people have combination skin – typically this is dry across the cheeks, but oily elsewhere, characteristically in the T zone – that is – across the forehead, down and round the nose.

Medical conditions associated with changes in the production/composition of sebum

Research has revealed that abnormalities in sebum may be important causative factors in the development of many common skin conditions.


Sebum production is increased in people with acne.  There is also a change in the sebum composition, with an alteration in the ratio of saturated to unsaturated fatty acids. An increase in lipid peroxidase activity stimulates the production of cytokines – the cell signaling molecules involved in the immune response – causing a flare-up of inflammation.

Acne patients have also been found to have lower Vitamin E levels, which results in inflammation.

Seborrheic Dermatitis

Large numbers of malassezia yeasts are commonly found on the skin surface of people suffering from seborrheic dermatitis. These yeasts break down lipids within the sebum, resulting in a lower level of triglycerides, and a relatively increased level of fatty acids. This imbalance then causes skin irritation.


People with rosacea don’t have a reduced sebum production but they do have a change in sebum composition.  Levels of myristic acid are increased, along with a reduced concentration of other long chain fatty acids. This makes the skin barrier function less effective.


In  Psoriasis, the sebaceous glands become atrophied – meaning they shrink. They seem to produce the same amount of sebum, but the sebum contains higher levels of phospholipids, triacylglycerols and cholesterol.

Atopic Dermatitis

People with atopic – allergic – skin conditions have dry skin. They experience trans-epidermal water loss because the barrier function of the skin is disrupted because of lower ceramide levels in the stratum corneum layer of the skin.

The skin microbiome

Healthy human skin is populated by a diverse range of microorganisms known as the skin microbiome. The skin is generally cool, dry, and has an acidic pH. 

The pH is acidic because of the large concentration of  fatty acids in the sebum.

The sebaceous glands favour colonisation by anaerobic organisms – these are organisms which require less oxygen – such as Propionibacterium acnes (P.acnes). P.acnes has an important role in maintaining the pH of the skin, by releasing the enzyme lipase. This breaks down the triycerides in sebum to produce fatty acids, and this then prevents the growth of other pathogenic bacteria, such as Staphylococcus aureus and Streptococcus pyogenes, which favour a more alkaline ph. 

Cosmetics, soaps, skin products – cleansers and moisturizers, all have the potential to disrupt the skin microbiome – by interfering with the natural role of sebum on the skin.

Looking after your skin.

Develop a good skincare regime

And stick to it. Be kind and gentle to your skin.  Pat it and stroke it, don’t rub vigorously or apply too much pressure – this only leads to more production of oil. Don’t use a rough flannel or a  loofah on your face.

Don’t over-wash your skin.

Sometimes you might be tempted to wash your face repeatedly but the body deals with this but just results in your body producing more. Twice a day, morning and night is enough. A 2006 study in which participants washed their faces once, twice, three, or four times a day, for 6 weeks, found no improvement over washing more than twice a day. Acne worsened in those washing only once per day.

How to use a cleanser

Many of the things that end up on your skin, such as makeup, or environmental pollutants, are not water-soluble. Therefore, cleansing is so important to avoid blocked pores. The term ‘cleanse’ – or using a cleanser – means applying anything to your skin which contains a surfactant. These are substances that dissolve grease. Cleansers include soaps, lipid-free cleansing lotions, liquid body washes, and cold creams. If the cleanser is too harsh, your skin may feel tight after using it, probably due to the rapid evaporation of water from the skin surface. Whatever you choose – most dermatologists believe a pH balanced cleanser (4-6.5) is advantageous as this helps maintain the normal skin flora and does not damage the lipid layer deeper in the stratum corneum of the skin. It’s important to choose a skin cleanser for your skin type. Acne sufferers may prefer an astringent, lipid-free cleanser. Patients with rosacea have very sensitive skin and need very mild products. If the skin is dry, the cleanser should contain humectants and emollients. There is a long list of ingredients in skin cleansers; water, surfactants, moisturizers, binders, lather enhancers, fillers (hardeners), preservatives, fragrances, and dyes/pigments. Many of these ingredients can cause local skin sensitivity. Choose simple, natural products especially for use on your face. 

Six key-steps for a good skin care routine.

Step One

Cleanse with soap and water. Soap is a surfactant and dissolves grease, so it will remove the surface grease from your skin. Use warm water, not scalding hot. Lather it, splash it off and pat it dry gently.

Step Two

Use a cleansing lotion – suitable for your skin type, and any medical skin conditions, and dab gently with cotton wool.

Step Three

The next step is a toner. Toners are gentle and soothing, PH balanced and may have additional anti-ageing properties for the skin. 

Step Four

Apply a serum. Serums are the Rolls-Royce of skin applications. A serum contains all the goodness of a moisturizer, but many of the additives of a normal moisturizer such as water and mineral oil have been left out. The result is a  small quantity of oily liquid which is super-full of antioxidants, vitamins, and minerals designed to be quickly absorbed and nourish your skin. A few drops morning and night are all that’s needed.

Step Five

Apply a moisturiser. Dermatologists recommend waiting one minute after applying a serum to allow this to ‘settle’ on the skin first.

Choosing the right moisturizer is important. Even people with oily skin need to moisturize. However, with oily skin choose a lotion, but with dry skin a thick cream or an ointment is preferable.  The skin actually becomes dry when it loses water, not oil. Moisturizers need to contain oil – to hold onto the water. 

Step Six

Apply a sun screen. Use at least as SP-30 and one which is oil and fragrance free. Some moisturisers contain a sunscreen.

Medical treatments for oily skin.

Another good option for oily skin is to apply a clay face mask.

Clay is a unique, natural product, rich in minerals and with specific biological properties advantageous for health. Clay has absorptive properties which are thought to draw out toxins/ impurities, and hence promote healing. It also has  antibacterial properties due to its metal content, for example, silver, copper and zinc, which have been shown to inhibit bacterial growth.

With the increasing problem of antibiotic resistance, there is much interest in the medical application of clays. 

Bentonite clay, for example, has several benefits.  When applied to the skin, it has a cleansing action,  to removing grease and dirt,  and also to unclog and shrink pores. These effects, along with its antibacterial effect, can also lead to improvements in acne.  

Dermatologists acknowledge the skin benefits of clay face-masks and agree they have a beneficial effect to absorb excess oil, unclog and shrink pores and reduce the skin surface shine. 

If your skin is excessively oily you may need the medical advice and help of a dermatologist.

Final Thoughts.

You are born with your skin type, and you can’t change it. However, you can identify what type of skin you have and look after your skin. However, even oily skin requires some oi,  for correct skin care. 

You can reduce oily skin by using the correct products and adopting a good skin care routine.  You will need to experiment with skin products to find the right ones for you. Look for natural products. Nature often has the answers! 

Think about your skin from first principles, respect your skin and nourish it.

In fact, sebum is a positive thing for our skin, and we need to embrace it – not hate it!

Sexual & Reproductive Healthcare Specialist & Freelance Healthcare Writer / Blogger.