A Dermatologist’s Guide to Balancing Oily Skin

Let’s start with the science. Sebum is the oily, waxy substance produced by sebaceous glands located throughout your skin – concentrated particularly on your face, chest and back. These glands are attached to hair follicles, and their job is to secrete sebum up through the pore to the skin’s surface.

What sebaceous glands actually do:

Sebaceous glands aren’t trying to ruin your makeup or make you feel self-conscious. They’re performing essential functions:

• Barrier protection: Sebum forms part of your skin’s protective lipid barrier, preventing water loss and keeping irritants out
• Acid mantle maintenance: The slightly acidic pH of sebum helps maintain your skin’s acid mantle, which protects against harmful bacteria
• Preventing transepidermal water loss (TEWL): Sebum creates a seal that reduces moisture evaporation from the skin’s surface
• Antioxidant delivery: Sebum contains vitamin E and other antioxidants that protect your skin from free radical damage

In other words, oil is biologically necessary. Without it, your skin would be vulnerable, dehydrated and unable to defend itself effectively.

The difference between a healthy glow and excess shine

So where’s the line between healthy sebum production and surplus oiliness? It comes down to regulation. Skin that produces the right amount of sebum looks luminous, plump and well hydrated. Skin that overproduces looks visibly shiny (particularly across the forehead, nose and chin), may have enlarged pores and often feels greasy to the touch within hours of cleansing.

If you’ve ever wondered how to control oily skin and why your skin produces more oil than seems necessary, you’re not alone. Excess sebum production rarely has a single cause – it’s typically a combination of genetic, hormonal and environmental factors.

• Barrier protection: Sebum forms part of your skin’s protective lipid barrier, preventing water loss and keeping irritants out
• Acid mantle maintenance: The slightly acidic pH of sebum helps maintain your skin’s acid mantle, which protects against harmful bacteria
• Preventing transepidermal water loss (TEWL): Sebum creates a seal that reduces moisture evaporation from the skin’s surface
• Antioxidant delivery: Sebum contains vitamin E and other antioxidants that protect your skin from free radical damage

In other words, oil is biologically necessary. Without it, your skin would be vulnerable, dehydrated and unable to defend itself effectively. 

Genetics and sebaceous activity

The size and activity level of your sebaceous glands are largely determined by genetics. If your parents had oily skin, you’re significantly more likely to as well. Some people simply have more sebaceous glands per square centimetre of skin, or glands that are more active and produce more sebum per follicle. This isn’t something you can change, but understanding it helps reframe oily skin as a biological variation rather than a personal failing.

Hormones and life stages

Androgens – particularly testosterone and its derivatives – stimulate sebaceous gland activity. This is why oil production fluctuates throughout life and even throughout the menstrual cycle:

• Puberty: Androgen levels surge, triggering increased sebum production (and often acne). Many people also have oily skin without acne – and that’s completely normal.
• Menstrual cycle: Many people notice their skin becomes oilier in the week before menstruation when progesterone levels rise.
• Pregnancy: Hormonal shifts can either increase or decrease oil production, depending on individual hormone levels.
• Perimenopause: Fluctuating estrogen and progesterone can lead to unpredictable changes in sebum production.
• Polycystic ovary syndrome (PCOS): Elevated androgens can lead to persistently oily skin.
• Stress: Cortisol stimulates oil production, which is why your skin may become noticeably oilier during high-stress periods.

Climate and environment

Your environment plays a significant role in how oily your skin appears and feels. High humidity can make oil more visible and prevent it from being absorbed into the atmosphere, and warm temperatures increase sebaceous gland activity.

Air conditioning and heating dry out the air, which can trigger compensatory oil production if your skin becomes dehydrated. Meanwhile, seasonal shifts mean skin is oilier in summer and more balanced in winter.

Over-cleansing and skincare mistakes

Perhaps the most frustrating cause of excess oil is the one you’re inadvertently creating yourself. Aggressive cleansing, harsh exfoliation and alcohol-heavy products strip away sebum too effectively, triggering your skin to produce even more oil to compensate. We’ll explore this in detail shortly, but it’s worth noting here: if your skin feels tight after cleansing and then becomes very oily within a few hours, you’re likely stuck in a strip-and-rebound cycle.

This is one of the most misunderstood conditions among people with oily skin. You cleanse and feel tight, uncomfortable. But within an hour, the shine returns and your skin looks greasy but feels parched. What’s going on?

It’s the difference between dehydration and dryness. Dry skin lacks oil, while dehydrated skin lacks water. You can have both simultaneously because sebum and hydration are separate functions.

When dehydrated, your skin triggers compensatory responses: increased transepidermal water loss (TEWL), excess oil production to seal moisture in and barrier dysfunction causing sensitivity. It feels tight after cleansing, fine lines are more pronounced, your makeup separates and products don’t sink in, there’s a dull tone despite that shine and even a rough texture. Read on to find out what to do.

Let’s talk about the strip-and-rebound cycle – or what some dermatologists call the strip-dry-overproduce pattern. Over-cleansing oily skin is the single most common mistake people make, and it’s rooted in a fundamental misunderstanding of how sebaceous glands work.

The logic seems reasonable: if your skin is too oily, remove the oil, right? Cleanse thoroughly. Use products that mattify. Avoid anything that might add more oil. The result? Skin that feels squeaky clean – that tight, almost squeaking sensation after washing. Here’s the problem: that tight feeling isn’t clean. It’s barrier damage.

When you strip away sebum too aggressively, several things happen:

1. Your skin’s pH is disrupted (healthy skin has a slightly acidic pH of around 4.5-5.5).
2. Your protective lipid barrier is compromised.
3. TEWL increases as water evaporates more readily from unprotected skin.
4. Your sebaceous glands receive signals that the barrier is damaged.
5. In response, they increase oil production to compensate.

Before you know it – in just a few hours – your skin is even oilier than before you cleansed. So you cleanse again, more aggressively. And the cycle continues.

Common culprits in the stripping cycle:

• Foaming cleansers with harsh surfactants (particularly sodium lauryl sulfate)
• Alcohol-heavy toners marketed as ’oil control’
• Overuse of BHAs (salicylic acid) – effective in moderation, damaging when used daily or multiple times per day
• Physical exfoliation (scrubs, brushes) used too frequently
• Clay mask overuse – clay is excellent for absorbing excess oil occasionally, but daily use strips the barrier