What Causes Oily Skin? 7 Reasons Your Skin Might Be Producing Excess Oil

Have you ever wondered why your skin seems to become oily just a few hours after cleansing? Or why your forehead and nose appear shiny, even when the rest of your face feels relatively normal?

Oily skin is a common skin type, and while excess shine can sometimes feel frustrating, the oil our skin produces plays an important role in maintaining its natural protective environment.

But what actually causes oily skin, and why do some people produce more oil than others?

The answer isn't always straightforward. Sebum production is influenced by several factors, including genetics, hormones, age and environmental conditions.

In this guide, we'll explore seven reasons your skin might be producing excess oil, why your skin type can change over time and how to care for oily skin without unnecessarily disrupting your skin barrier.

What Is Sebum and Why Does Our Skin Produce It?

Before looking at the causes of oily skin, it's helpful to understand what sebum is and why our skin produces it.

Sebum is an oily substance produced by sebaceous glands, which are found throughout much of the skin, particularly on the face, scalp, chest and upper back.

It contains a mixture of lipids, including triglycerides, wax esters and squalene, and contributes to the natural oils present on the skin's surface (Picardo et al., 2009).

Sebum helps lubricate the skin and hair and contributes to the skin's protective surface environment.

Although it is often associated with shine, blocked pores and blemishes, sebum itself isn't something we should be trying to eliminate.

Everyone produces sebum, but the amount varies considerably between individuals.

When the sebaceous glands produce higher amounts of sebum, the skin may develop a noticeably oily or shiny appearance.

1. Genetics and Your Natural Skin Type

One of the main reasons some people have oily skin is genetics.

Our genes influence several characteristics of the skin, including sebaceous gland activity and how much sebum is naturally produced.

This means that if oily skin runs in your family, you may be more likely to experience it yourself.

Some people naturally have more active sebaceous glands, resulting in increased oil production across the face.

Others may produce less sebum and experience a drier skin type.

Because genetics plays an important role, oily skin isn't necessarily caused by using the wrong skincare products or not cleansing your face frequently enough. It's simply a natural characteristic of your skin.

2. Hormonal Changes

Hormones are another important factor influencing sebum production.

In particular, hormones known as androgens play a significant role in stimulating sebaceous gland activity.

Androgens are present in both males and females, although their concentrations differ.

Changes in hormonal activity can influence how much oil the skin produces, which helps explain why oily skin can become more noticeable during certain stages of life.

Puberty

During puberty, androgen activity increases, stimulating sebaceous glands and contributing to greater sebum production.

This is one reason oily skin and acne are particularly common during adolescence.

Menstrual Cycle

Hormonal fluctuations throughout the menstrual cycle may influence skin characteristics, although changes in sebum production vary between individuals.

Some people notice increased shine or blemishes at particular points in their cycle.

Pregnancy and Other Hormonal Changes

Hormonal changes during pregnancy and other life stages can affect the skin, although some people experience increased oiliness while others notice dryness or sensitivity.

If your skin changes significantly during a period of hormonal fluctuation, it may be worth adjusting your skincare routine to suit its current needs.

3. Age and Changes in Sebum Production

Our skin changes naturally as we age, and sebum production is no exception.

Sebaceous gland activity typically increases during puberty, influenced by hormonal changes.

During adulthood, oil production may remain relatively stable for some people, while others notice gradual changes.

Research suggests that sebum production often declines with advancing age, although the timing and extent of these changes differ between individuals and can be influenced by hormonal factors (Zouboulis et al., 2008).

This means someone who experienced very oily skin during their teenage years may find their skin becomes less oily later in adulthood.

However, oily skin doesn't automatically disappear as you get older.

Some people continue to experience excess oil production well into adulthood.

As your skin changes, it's worth reassessing your skincare products rather than assuming that the same routine will always suit your needs.

4. Hot Weather and Humidity

Have you noticed that your face seems oilier during the summer months or when you're somewhere hot and humid?

Environmental conditions can influence how oily the skin appears and feels.

Research has found associations between temperature, humidity and measurements of sebum at the skin's surface, although the relationship is complex and varies between individuals.

During warmer weather, increased sweating can also contribute to the sensation of having greasy or shiny skin.

This is particularly noticeable around the forehead, nose and chin.

In humid conditions, you may also find that heavier skincare products feel less comfortable on the skin.

During warmer months, some people prefer lightweight moisturisers and non-greasy sunscreen formulations.

However, it's still important to maintain hydration and daily sun protection, even when your skin feels oily.

5. Stress and Its Effects on the Skin

Stress can influence several biological processes throughout the body, including those involved in skin function.

The skin contains receptors and signalling pathways that respond to stress-related hormones and neuropeptides.

Research suggests that certain stress-related pathways may influence sebaceous gland activity and inflammation within the skin (Zouboulis et al., 2002).

However, this doesn't mean that stress will always cause oily skin, and the relationship between stress and sebum production is complex.

Stress may also affect skincare habits, sleep patterns and existing skin conditions, which can influence how the skin looks and feels.

If you notice changes in your skin during particularly stressful periods, maintaining a gentle and consistent skincare routine may help reduce unnecessary irritation.

6. Skincare Products and Cleansing Habits

Although your skincare routine doesn't usually determine your natural skin type, the products you use can affect how oily your skin appears and how comfortable it feels.

For example, rich or heavy formulations may leave a noticeable residue on the skin, making it appear shinier.

On the other hand, harsh cleansers or excessive exfoliation can remove surface lipids and contribute to dryness, irritation and disruption of the skin barrier.

It's sometimes suggested that stripping the skin of its natural oils causes it to compensate by producing more oil. However, there is limited scientific evidence that harsh cleansing directly causes an increase in sebum production.

What we do know is that harsh cleansing and over-exfoliating can disrupt the skin barrier, leading to dryness, dehydration and irritation. This is why it's important to choose a gentle cleanser that helps remove excess oil and daily impurities without compromising the skin's natural moisture balance.

This can result in skin that feels dry after cleansing but becomes shiny again throughout the day.

How to Choose Skincare for Oily Skin

When choosing products for oily skin, consider the following:

• Use a gentle cleanser that removes excess surface oil without leaving the skin feeling stripped.
• Avoid washing your face excessively throughout the day.
• Introduce exfoliating products gradually and avoid over-exfoliation.
• Use a suitable moisturiser to help maintain hydration.
• Choose a broad-spectrum sunscreen that feels comfortable on your skin.

For more practical advice, explore our guide on how to control oily skin without stripping your skin barrier.

7. Underlying Skin Conditions and Other Factors

Sometimes, oily skin may be associated with other skin concerns or underlying conditions.

For example, acne is influenced by several factors, including increased sebum production, changes in skin cell turnover, inflammation and the activity of bacteria within the hair follicles.

However, oily skin doesn't automatically mean that someone will develop acne.

Similarly, seborrhoeic dermatitis is a skin condition that commonly affects areas rich in sebaceous glands, including the scalp, eyebrows and sides of the nose.

It can cause redness, flaking and irritation, rather than simply increased oiliness.

Certain medications and hormonal conditions may also influence sebum production or skin appearance.

If you experience a sudden or significant change in oiliness, particularly alongside persistent acne, changes in menstrual regularity or other new symptoms, it's worth discussing this with a healthcare professional.

Why Is My Face Suddenly So Oily?

If your skin has recently become noticeably oilier, there may be several possible explanations.

Changes in hormones, environmental conditions, skincare products or certain medications may all influence how oily your skin appears.

For example, you might notice increased shine after moving to a warmer climate, changing your moisturiser or experiencing hormonal fluctuations.

It's also worth considering whether your skin is genuinely producing more sebum or whether a new product is leaving a heavier finish on the skin.

If you've recently changed your skincare routine, try assessing how your skin feels after cleansing and throughout the day.

Sudden changes that are persistent, pronounced or accompanied by other symptoms should be assessed by a healthcare professional rather than automatically attributed to skincare.

Does Oily Skin Mean You're Not Cleansing Properly?

No. having oily skin doesn't mean your face is dirty or that you're not cleansing it correctly.

Sebum is produced naturally by the sebaceous glands, and the amount your skin produces is largely influenced by biological factors.

Although cleansing removes excess oil from the skin's surface, it doesn't permanently stop the sebaceous glands from producing sebum.

Washing your face more frequently isn't necessarily more effective and can contribute to irritation if your skin is repeatedly exposed to harsh cleansers.

For most people, gently cleansing twice daily is a suitable starting point.

Can You Permanently Reduce Sebum Production?

Because sebum production is influenced by genetics and hormones, it's not usually possible to permanently change your natural skin type through everyday skincare products.

However, some skincare ingredients and medical treatments may help manage excess oil or conditions associated with increased sebum production.

For example, niacinamide has been looked into for its potential to reduce the appearance of surface oiliness, although the results depend on the formulation and the evidence remains limited.

Medical treatments that affect sebaceous gland activity may be prescribed for certain skin conditions, such as acne, but these require professional assessment and aren't necessary for most people with naturally oily skin.

For everyday skincare, the aim should be to manage surface oil, maintain hydration and support the skin barrier.

How to Care for Oily Skin

While you may not be able to change your natural skin type, choosing suitable skincare products can help manage the appearance of excess oil and maintain skin comfort.

A simple routine might include:

1. Gentle cleansing: Remove excess surface oil, dirt and impurities without unnecessarily stripping the skin.
2. Appropriate exfoliation: Use suitable exfoliating ingredients to help remove dead skin cells and improve the appearance of skin texture.
3. Moisturising: Maintain hydration and support the skin barrier with a suitable moisturiser.
4. Daily SPF: Protect the skin against UV exposure with a broad-spectrum sunscreen.

Remember that oily skin can also be dehydrated, so maintaining hydration remains important even if your skin appears shiny.

You can learn more in our guide to oily but dehydrated skin.

For a complete morning and evening routine, explore our best skincare routine for oily skin.

Final Thoughts

Oily skin is a natural skin type influenced by several factors, including genetics, hormones, age and environmental conditions.

Although excess sebum can contribute to shine, visible pores and congestion, it also plays an important role in the skin's natural protective environment.

Understanding what causes oily skin can help you make more informed skincare choices and avoid unnecessary habits such as over-cleansing or excessively exfoliating.

Rather than trying to eliminate oil production altogether, focus on a consistent skincare routine that helps remove excess surface oil, maintain hydration and support your skin barrier.

For a broader overview of oily skin, including how to identify your skin type and choose suitable products, read our Ultimate Guide to Oily Skin.

Frequently Asked Questions

References

Picardo, M., Ottaviani, M., Camera, E. and Mastrofrancesco, A. (2009). Sebaceous gland lipids. Dermato-Endocrinology, 1(2), 68–71.

Zouboulis, C.C., Chen, W.C., Thornton, M.J., Qin, K. and Rosenfield, R. (2007). Sexual hormones in human skin. Hormone and Metabolic Research, 39(2), 85–95.

Zouboulis, C.C., Seltmann, H., Hiroi, N. et al. (2002). Corticotropin-releasing hormone: An autocrine hormone that promotes lipogenesis in human sebocytes. Proceedings of the National Academy of Sciences, 99(10), 7148–7153.

Zouboulis, C.C., Baron, J.M., Böhm, M. et al. (2008). Frontiers in sebaceous gland biology and pathology. Experimental Dermatology, 17(6), 542–551.

For further information about oily skin and skincare, visit the American Academy of Dermatology.