Why your skin produces Oil : A scientific breakdown

When people think of having oily skin they frequently associate it with acne, clogged pores and bad skin care habits. In reality, however, the production of oil from the skin is a normal and necessary biological process, according to oily skin science. Your skin produces oil to protect itself, keep itself hydrated, and work well with the rest of your body.

The oily substance that is found on the surface of your skin is called sebum and originates from very small glands located in the dermis of the skin. The formation of oil has a lot to do with factors such as genetics, hormones, stress, geographic location, and the use of skin care products. Even though having too much oil on your face may cause breakouts or shine, trying to remove all oil will compromise the protective ability of your skin.

Once you know the reasons for the production of oil it will be much easier to understand how oily skin acts and the reason why aggressive treatments for oily skin usually cause more harm than good.

What Is Skin Oil? - Understanding Sebum and Its Functions 

Sebum is scientifically known as skin oil, is a waxy, lipid-rich substance produced by sebaceous glands. Sebum is made up of several components including:

• Triglycerides 

• Wax esters

• Squalene

• Free and fatty acids

• Cholesterol 

Skin’s natural protective coating is formed by these lipids. 

What Does Sebum Do? 

Some important biological functions sebum serves :

1. Protecting the Skin Barrier

Sebum provides a layer of protection for the skin by acting as a barrier to environmental irritants, pollutants and microbes.

2. Reducing Trans-Epidermal Water Loss

Sebum also slows trans-epidermal water loss (TEWL), allowing for moisture retention in the skin.

3. Lubricating the Skin

Sebum provides smoothness and flexibility to the skin and decreases friction.

4. Supporting Antimicrobial Defense

Sebum contains certain types of fatty acids that help to regulate the microbial balance on the surface of the skin.

According to the science of oily skin, sebum is not inherently bad. Most problems arise when excess sebum combines with other, older skin cells (dead), and when there is a presence of an inflammatory process.

If you strip all the oil off of your skin, it may cause damage to the skin barrier and lead to increased irritation, as well as potentially leading to greater production of oil.

How Sebaceous Glands Work 

Sebaceous glands are small glands that produce oils and are found just under the surface of the skin. The sebaceous glands are present in almost every region of the body, but the majority are located in areas of the body that contain hair follicles, including:

• Forehead

• Nose

• Chin

• Scalp

• Upper chest

Because there are so many sebaceous glands in these locations, the t-zone on the face tends to be oily.

How Is Sebum Produced? 

Sebocytes produce (store) lipids that are found in sebaceous glands. As cells mature, they become broken down, thus producing oil (sebum), which is secreted through the hair follicle to the skin surface.

There are several types of stimulation for sebaceous growth:

• Hormones

• Stress

• Genetics

• Temperature (environmental factors)

• Inflammation
  

When there is excessive oil produced from sebaceous glands, this is usually caused by overstimulation of those glands.

For those with larger or more active sebaceous glands, they might continuously have oily skin despite their cleansing/personal care routine.

The Role of Hormones in Oily Skin

One of the biggest causes of oily skin are hormones.

Androgens and DHT 

Sebaceous gland activity is stimulated by androgens, which are hormones. An androgen noted for its high-powered use is a type called dihydrotestosterone (DHT) which produces sebum production at a high level.

There is often an increase in androgens at puberty making oily skin and hormonal acne very much more prevalent among adolescents.

Hormonal Fluctuations 

Hormonal oily skin can occur for several reasons during:

• The menstrual cycle

• Pregnancy

• Stress

• The condition known as polycystic ovary syndrome (PCOS)

Cortisol is a stress hormone which may indirectly cause oiliness or increased inflammation.

Why Hormonal Acne Happens 

Acne is actually caused by a combination of the following four factors, which includes excess sebum:

• Increased Oil Production

• Buildup of Dead Skin Cells

• Overgrowth of Bacteria

• Inflammation
  

Due to this combination of factors, acne caused by hormones will often appear on the lower face and jawline, as this area contains many sebaceous glands.

Skin Microbiome and Oil Production 

Our skin is home to billions of microorganisms collectively known as the skin microbiome. 

This ecosystem includes:

• Bacteria

• Fungi

• Viruses

• Mites

The fact is that many microbes help maintain skin balance, since not all bacteria are harmful. 

Oil and Acne Bacteria

Cutibacterium acnes is one bacterium that is closely linked with acne. This bacteria feeds partly on sebum. However, bacteria and oily skin alone do not automatically cause acne. 

Microbiome imbalance and inflammation plays a major role.

How Overwashing Disrupts the Skin 

Harsh cleansing can negatively affect the microbiome and break down the skin's protective barrier. 

This may lead to: 

• Irritation

• Increased inflammation

• Increased oiliness 

• Greater sensitivity 
  

Research has demonstrated that oily skin is not necessarily “dirty skin”. Generally, oily skin may be responding to an inflammatory process, hormonal changes, or a disrupted skin barrier rather than poor hygiene.

Oil vs Hydration - They Are Not the Same 

The biggest misconception about skincare is that oil and hydration are the same things.

What is the difference?

• Lipids produced by sebaceous glands refers to oil.

• The water content within the skin refers to hydration.

So therefore, a person can have oily but dehydrated skin at the same time.

What Is Dehydrated Oily Skin? 

When you don’t have enough moisture in your skin but do have excess oil, you have dehydrated oily skin. The conditions that may lead to this include:

• Over-cleansing

• Excessive exfoliation

• Drying acne medications

• Environmental stress

When the skin barrier gets damaged, transepidermal water loss (TEWL) increases, the skin may react by producing more oil.

Why Moisturizer Still Matters 

Oily skin also requires moisture to keep it hydrated and to form a barrier on the skin.

Lightweight moisturizers with the following ingredients will help prevent drying out the skin by providing hydration, while not feeling greasy to the touch:

• Glycerin

• Hyaluronic Acid

• Niacinamide

To properly manage oily skin, it is important to understand the differences between hydration vs oil.

Product Formulation and Oil Interaction 

All skincare products do not interact with oily skin in the same way.

Cleansers and Surfactants

Surfactants that are present in cleansers remove oil and debris. The cleansers that are extremely harsh may strip the skin barrier and worse oiliness.

For long term use gentle cleansers are usually more effective.

Non-Comedogenic Skincare

Skincare products that are non-comedogenic are designed to reduce the likelihood of clogging pores.

People with oily skin often benefit from lightweight formulations such as: 

• Gel moisturizers

• Water -based serums

• Lightweight emulsions

Occlusives vs Humectants

Humectants attract water into the skin. Examples include:

• Glycerine

• Hyaluronic acid

To reduce water loss, occlusives form a protective seal.

Balanced formulations help maintain hydration without overwhelming oily skin.

Helpful Ingredients for Oily Skin 

Do remember that your goal should not be to remove sebum completely, but to regulate and maintain the oil production, reduce inflammation, support skin barrier and minimize clogged pores without damaging the skin, and for that reason choosing the right ingredient is an important part of skincare for oily skin.

Niacinamide

Niacinamide (B3) helps regulate oil production, decreases redness and provides support to the skin barrier. According to the study published in the Journal of Cosmetic and Laser Therapy (2006), when applied to the skin, topical niacinamide acid lowered the amount of sebum in individuals with oily skin. 

Benefits:

• Controls for excess oil

• Repairs skin barrier

• Reduces acne-related swelling

Salicylic Acid

Salicylic Acid , an oil based exfoliant, aids in the removal of excess sebum and dead cells from the surface of the skin, enabling greater absorption into the pores.

Benefits:

• Elimination of clogged pores

• Treatment of acne while battling oil production

• Improvement of blackheads & whiteheads

Overuse of Salicylic Acid may lead to damage of the skin barrier and increased levels of irritation.

Azelaic Acid

Azelaic Acid can reduce inflammation, acne and post-acne marks with a gentler method than some common exfoliants. Research in Clinical, Cosmetic and Investigational Dermatology shows Azelaic Acid to be very effective in helping people who have oily skin with moderate-to-severe acne.

Benefits of Azelaic Acid:

• Treats Hormonal Acne

• Increases Clarity of Pores

• Reduces Redness and Pigmentation

Hyaluronic acid

Dehydrated oily skin can be a concern. You can help with your dry skin by using hyaluronic acid, which hydrates your skin but does not cause greasiness.

Benefits:

• Hydration

• Support for the skin barrier

• Hydration for dehydrated oily skin

Green Tea Extract 

Green Tea has many antioxidants, which may also help lessen sebaceous gland activity and reduce inflammation.

Benefits:

• Reduction of oily skin

• Antioxidant protection

• Support for acne-prone skin

Green Tea has many antioxidants, which may also help lessen sebaceous gland activity and reduce inflammation.

FAQs

1. What are the signs of dehydrated oily skin? 

Dehydrated oily skin actually produces excess oil while still lacking hydration or water. Common signs include:

• Shiny, greasy skin but a feeling of tightness

• Flaky patches on oily T-Zone

• Dry feel on skin after cleansing

• Increased sensitivity to skin

• Redness

• More breakouts despite using acne products 

• Appearance of tired or dull skin

The problem arises due to damage to the skin barrier which is caused by increased trans-epidermal water loss (TEWL). As a result, your skin produces too much oil as an attempt to replace water lost. 

2. Why does my skin get oily so fast? 

Fast oil production is commonly due to overactive sebaceous glands, hormonal fluctuations, hereditary factors, stress levels and the use of harsh skincare products. Washing the face aggressively may also stimulate rebound oil production from damaging the skin barrier.

Individuals with oily skin usually demonstrate increased amounts of shine in areas that have a greater number of sebaceous glands, including the forehead, nose and chin.

3. Can dehydration cause oily skin? 

Absolutely! Dehydrate skin can also exacerbate your Oily Skin. When you don’t have enough water in your body your Oily Skin may produce more oil to protect itself. Therefore many people have oily but dry skin after using too much exfoliation, cleansers, & acne treatments.

Using lightweight hydration will help with creating balance & not making the skin oily.

4. Is oily skin genetic? 

The genetics behind oily skin is important. Your genetic makeup determines:

• The size of your sebaceous glands.

• How sensitive you are to hormones.

• How much sebum (oil) your body produces.

• Your likelihood of getting acne.

If oily skin runs in your family, it is possible that you will also produce more oil than average.

5. Does oily skin cause acne? 

Acne is not caused specifically by oily skin, but rather by excessive sebum (oil), dead skin cells, inflammation, and acne-causing bacteria getting clogged in the pores and forming acne.

Hormones, clogged pores, skin bacteria and inflammatory conditions are all contributing factors to the development of acne.

This is not to say that there is a large difference in the amount of oiliness between people with acne and people who do not have acne, but rather that hormonal fluctuations or fluctuations in the microbiome can determine the level of sebum production (oil) and whether a person develops acne.

6. Why is my nose always oily? 

Sebaceous glands produce sebum all over the body, especially in the T-zone, especially on the nose. There tends to be a lot of sebum or oil in the T-zone compared to the rest of the face.

This area can have a lot of oil produced due to environmental heat, hormonal levels, and stress levels.

7. Can hormones increase oil production? 

Absolutely! Hormones are among other reasons why we have excessively oily faces. Sebaceous glands produce an excess of natural oil when stimulated by androgens, particularly dihydrotestosterone (DHT).

During these times of life your hormones fluctuate, and as a result, your face may be excessively oily:

• Puberty

• Menstrual cycle

• Pregnancy

• Stress

• Hormonal disorder (such as polycystic ovary syndrome; PCOS)

Changes in hormones are also extremely common for women who experience breakouts from acne.

8. Does oily skin age slower?

Sebum provides moisture retention reducing the visible signs of aging. With this said, oily skin ages, demonstrates sun damage and continues to lose collagen like all skin types. Therefore it is recommended that you take care of your oily skin by providing your skin with the necessary hydration, skin care and protection (sunscreen).

Summary

In science, oily skin refers to the amount of oil produced on your skin; therefore, oil production is a normal biological process that protects the skin and provides support for the skin's integrity. Sebum, the oil found in your skin, serves to protect the skin barriers, reduce evaporation or loss of water from the body and maintain a microflora balance.

Sebum production is affected by hormones, heredity, the skin's microbiome and the use of skin-care products. The focus of modern oily skin care is not on removing oil but on restoring harmony to the skin's barrier, hydration and overall integrity.

With a greater understanding of the science behind oily skin, one can make better skin-care choices to support optimal function of the skin over time.

Recommended Products by Blue Nectar:

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References:

https://pmc.ncbi.nlm.nih.gov/articles/PMC5605215/

https://my.clevelandclinic.org/health/body/24538-sebaceous-glands

https://www.sciencedirect.com/science/article/pii/S0022202X15308691

https://www.health.harvard.edu/blog/polycystic-ovarian-syndrome-and-the-skin-202104292552

https://pmc.ncbi.nlm.nih.gov/articles/PMC6920876/