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Causes d'une peau grasse.

Why do we have oily skin?

Whether the skin appears oily and shiny, the pores are enlarged, the complexion is dull, or blemishes form... these are daily occurrences for individuals with oily skin. Let's explore together the origins of this skin imbalance.

What are the signs of oily skin?

An oily skin is considered a skin type characterized by a shiny and glossy appearance that extends across the entire face, unlike combination skin which is limited to the T-zone (forehead, nose, chin). This is due to an imbalance in the quantity of sebum, meaning that this type of skin naturally secretes excess sebum, produced by the sebaceous glands located in the dermis. However, this sebum is a component of the hydrolipidic film of the epidermis, and therefore contributes to the protection of the skin against external aggressions and fights against dryness, by covering it with a light oily layer.

Indeed, this condition promotes the accumulation of impurities (pollutants, dust, etc...), which can in turn clog the skin pores and thus lead to the appearance ofblemishes such as comedones, pimples... Moreover, this significant sebum production in the sebaceous glands enlarges the pores (opening of the pilosebaceous follicle on the skin surface) to facilitate its evacuation: they then appear more visible.

But what explains this excessive sebum production? This hypersecretion of sebum depends on internal causes, but can also be influenced by external factors.

Note : Oily skin is not all disadvantageous. This hypersecretion of sebum provides it with better protection against external aggressions. Another advantage, this type of skin resists aging better, with signs of age appearing a bit later. It is therefore better to try to regulate the production of sebum with suitable products, instead of trying to eliminate it.

The internal causes of oily skin.

The root cause of oily skin is an overproduction of sebum (hyperseborrhea). Various internal factors can be responsible for this imbalance:

  • Hormonal Disorders:

    The production of sebum is regulated by estrogens and androgens. Female hormones inhibit its production, unlike male hormones. When the balance between hormones is disrupted, sebum production is affected. A decrease in estrogen production or an increase in androgen production can lead to oily skin. Hormonal disturbances occur during puberty, which is why teenagers often have oily skin. Another example, in women, before the menstrual period, the level of estrogen drops sharply accompanied by an increase in the level of progesterone. At this stage of the menstrual cycle, the skin becomes oilier.

  • The distribution of sebaceous glands on the body:

    The sebaceous glands are responsible for the secretion of sebum. However, they are unevenly distributed across the body's surface. Certain areas are thus rich in sebum compared to others: the face, the upper back, the scalp, and the abdomen. On the face, the distribution of sebaceous glands is also irregular, which is why the T-zone and cheeks become oily quickly compared to the rest of the face (eyelids, temples...).

  • The gender:

    Hormonal imbalances are responsible for oily skin. Girls are the first to experience oily skin, as their puberty begins before boys. Once reaching adulthood, men's skin secretes sebum excessively, which means they are more likely to deal with oily skin compared to women.

Environmental factors responsible for oily skin.

Apart from internal causes, oily skin can also be triggered by external factors:

  • Thediet :

    The consumption of foods high in quick sugars and dairy products promotes the production of lipids by the sebaceous glands. Therefore, a healthy diet can balance the skin's sebum production. Alcohol consumption stimulates sebum synthesis.

  • Stress:

    Emotions that can cause stress and anxiety can disrupt hormone functions. They also increase body temperature, thereby stimulating sebum production. It has been observed that skin tends to become oily quickly in the summer due to the increase in skin temperature.

  • External aggressions:

    Sebum production can increase when the skin undergoes intense stripping or regular aggressions. These include UV rays, harsh treatments, care unsuitable for the skin type, pollution, etc...


  • THIBOUTOT D. Regulation of human sebaceous glands. Dermatology Foundation (2003).

  • MAIBACH H. I. & al. Oily skin: an overview. Skin Pharmacology and Physiology (2012).


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