Oily skin is a skin type with well-developed sebaceous glands that produce a lot of sebum. It's marked by heavy shine centered on the forehead, nose, and chin (T-zone), enlarged-looking pores, and frequent acne.
Many people with oily skin choose harsh cleansing and drying care, thinking they'll "reduce sebum." Yet this often paradoxically worsens sebum production.
Causes of excess sebum in oily skin
1. Genetics and hormones
The most fundamental cause. Skin with many or sensitive androgen receptors produces sebum actively. Sometimes the sebaceous glands themselves are genetically large.
2. Over-cleansing and dryness
When skin becomes too dry, the brain receives a "low moisture" signal and actually increases sebum. Washing 3+ times a day with a harsh cleanser is a classic cause of this vicious cycle.
3. Lack of moisturizing
Skipping moisturizer due to the myth that "oily skin doesn't need moisture" dries the skin and increases sebum. An oil-free hydrating moisturizer is essential even for oily skin.
4. High-GI foods, dairy
Research suggests foods that quickly raise blood sugar, and dairy, can raise insulin and stimulate androgen secretion, increasing sebum.
Proper cleansing for oily skin
Frequency: Twice a day (morning, evening). 3+ times causes barrier damage and rebound sebum.
Temperature: Lukewarm water. Hot water irritates skin and enlarges pores.
Cleanser: A pH 4.5–5.5 acidic foam cleanser. Avoid strong surfactants (SLS).
Double cleansing: Only when wearing sunscreen or makeup. Daily oil cleansing is unnecessary.
Moisturizing principles for oily skin
Choose a non-comedogenic moisturizer in a water-gel or hydrating-essence texture. Products centered on hyaluronic acid, glycerin, and niacinamide suit oily skin. Oil-free products help reduce clogged pores.
Pore care
Pores can't be permanently reduced in size structurally. But managing the causes of enlarged-looking pores (sebum, keratin buildup, reduced elasticity) improves their appearance.
- BHA (salicylic acid): oil-soluble, it directly dissolves sebum inside pores. Use 2–3 times a week
- Niacinamide: suppresses sebum + improves elasticity around pores
- Clay masks: effective at absorbing pore sebum, 1–2 times a week
Choosing sunscreen for oily skin
The main reasons oily skin avoids sunscreen are white cast and shine. Choose a light water-based or gel-type sunscreen. Lately many "non-greasy" and "matte finish" sunscreens are available, widening the options.
For oily skin, sebum itself serves a protective function, so the goal is balanced management rather than complete removal. Remember that over-cleansing and skipping moisturizer are the most common mistakes.