What is combination skin?

Combination skin is a skin type characterized by an uneven distribution of sebaceous activity across the face.

Typically, the T-zone—meaning the forehead, nose, and chin—exhibits elevated sebum production, resulting in more pronounced shine, sometimes coupled with enlarged pores or slight imperfections. In contrast, the cheeks, temples, and eye area tend to be drier and occasionally more prone to tightness.

This duality of combination skin primarily stems from differences in the density and activity of sebaceous glands in different areas. Indeed, the T-zone contains a higher number of sebaceous glands, tasked with sebum synthesis and whose activity is stimulated by hormonal factors—particularly androgens—and environmental factors. Sebum, composed mainly of triglycerides, wax esters, and squalene, plays a vital role in protecting the skin against dehydration and external aggressors. However, when produced in excess, it can leave the skin looking shiny and glossy, lead to pore blockage, and contribute to the development of blemishes.

In contrast, the cheeks of individuals with combination skin often exhibit a lipid organization similar to that of dry skin and suffer from a lipid deficiency. As a reminder, lipids, such as ceramides, serve as intercellular cement in the stratum corneum, filling the spaces between corneocytes to maintain the cohesion of the skin barrier. They thus help limit water loss and protect the skin from external aggressors, for example by restricting the penetration of allergens and microorganisms. The contrast with the T-zone therefore results from heterogeneity in barrier function across the face.

Find here our evidence-based recommendations for caring for combination skin.

The causes of combination skin are multiple and revolve around genetic, hormonal, environmental, and behavioral factors. Genetics plays a central role in the distribution and activity of the sebaceous glands, even though, in general, more sebaceous glands are found in the T-zone. Hormonal variations, especially during adolescence or throughout the menstrual cycle, can also contribute. Androgens, particularly testosterone and its active form, dihydrotestosterone, stimulate sebaceous gland activity. The environment likewise influences combination-skin physiology. A dry or cold climate promotes dehydration and the emergence of dry patches, while heat and humidity increase sebum production, amplifying shine and imperfections in oily areas. These variations can be seasonal: in summer, excess sebum is more common, whereas in winter, dry zones prevail.

This has in fact been confirmed by a study conducted on 46 volunteers aged 21 to 37, which showed that skin type can vary with the seasons. The researchers measured sebum secretion separately on the T-zone (forehead, nose, chin) and the U-zone (cheeks, jawline). In summer, 71.7% of the participants had a combination skin profile, compared to less than 50% in autumn (26.8%), winter (41.3%), and spring (34.8%). The study also found that only 10.8% of the volunteers maintained a single skin type throughout the year, while the majority showed significant differences in sebum production between the T-zone and the U-zone for at least one season, corresponding to combination skin.

• YOUN S. W. & al. Regional and seasonal variations in facial sebum secretions: A proposal for the definition of combination skin type. Skin Research and Technology (2005).

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

• RICHARD M. A. & al. La peau des Français. Analyse des caractéristiques de notre peau à partir de l’étude Objectifs Peau. Annales de Dermatologie et de Vénéréologie (2017).