Closed comedones — what causes them and how to clear them.

Closed comedones are non-inflamed acne lesions — follicles blocked by keratin and sebum, covered by a thin layer of skin that prevents the oxidation that gives open comedones (blackheads) their dark appearance. They typically appear as small flesh-coloured or slightly white bumps, most commonly concentrated on the forehead, chin, and cheeks. They are not infected, not inflamed, and do not respond to treatments designed for inflamed acne.

The distinction matters because most people treat them with products targeted at a different problem.

What causes closed comedones

The root mechanism is follicular hyperkeratinisation. Keratinocytes lining the inside of the follicle accumulate faster than normal, or fail to shed in an orderly way, building up as a plug inside the follicle. Combined with sebum production, this plug gradually distends the follicle. Because the follicular opening remains covered by skin — unlike a blackhead — the contents are sealed in.

Several factors accelerate this process.

Hormonal fluctuation. Androgens stimulate sebaceous gland activity. Periods of hormonal change — adolescence, certain phases of the menstrual cycle, stopping hormonal contraception — frequently correlate with increased comedonal activity. Topical treatments operate on the follicle; they do not address the hormonal driver.

Comedogenic product formulation. Some ingredients in skincare and makeup occlude follicles at higher concentrations or in certain formulations. Isopropyl myristate, certain heavy mineral oils, and some silicone derivatives are most frequently cited. This is relevant when comedones are concentrated in areas of consistent product application — around the forehead where a moisturiser is applied heavily, or along the jaw where a primer is layered.

Incomplete cleansing. Residual sunscreen, heavy product, and oxidised sebum left on skin create conditions for follicular accumulation. Oil cleansing is particularly effective at dissolving sebum and sunscreen residue that water-based cleansers do not fully remove.

Why most spot treatments do not work

Benzoyl peroxide and high-concentration salicylic acid spot treatments are designed for inflammatory acne — pustules and papules where C. acnes bacteria are involved. Applying them to a non-inflamed closed comedone addresses an irrelevant mechanism. There is no significant bacterial component in a closed comedone. The sealed follicle also limits penetration of any topical applied in brief contact time, which is why leave-on formulations outperform rinse-off at the same concentration.

Physical scrubbing has no meaningful effect on follicular plugs. The plug is inside the follicle, not on the surface. Scrubbing removes surface cells and introduces friction — which can trigger inflammation where none existed before.

What actually works

Retinoids are the primary treatment for closed comedones and the most strongly evidence-supported option. Adapalene, tretinoin, and retinol normalise follicular keratinisation at the cellular level — they correct the process that causes plugging, not just the visible outcome. Adapalene at 0.1% (available over the counter in most Australian pharmacies) is the most accessible starting point. Tretinoin requires a prescription but is more potent. Retinol has the same mechanism with a slower and gentler onset.

The timeline for retinoid-driven improvement in comedonal texture is eight to twelve weeks of consistent use. This is a common point of abandonment — the purging phase in the first four to six weeks can produce temporary worsening as retinoids accelerate the clearing of existing follicular contents. This is expected and resolves.

Salicylic acid (BHA) is oil-soluble, which allows it to penetrate into oil-filled follicles and exfoliate the follicle lining directly. At 0.5–2% in a leave-on formulation — serum or toner rather than rinse-off cleanser — it is the most effective topical exfoliant for comedonal acne. It works best as a consistent supporting treatment alongside a retinoid rather than as a primary standalone. Two to three evenings per week is a sensible frequency; daily high-strength use risks barrier compromise.

AHAs — glycolic acid, lactic acid — work at the skin's surface, accelerating corneocyte turnover. They support comedone clearing indirectly by removing dead surface cells that contribute to follicular obstruction, but they do not penetrate the follicle the way BHA does. They are a secondary option, useful as part of a broader routine but not the first thing to reach for.

Reviewing product ingredients

If closed comedones persist despite consistent treatment, reviewing the ingredients in every product applied to the affected area is the next step. Cross-reference moisturiser, SPF, primer, and foundation against frequently comedogenic ingredients. This is not an exact science — comedogenicity studies are conducted in rabbit ear models, not on human facial skin — but the practical check is useful. Switching to a non-comedogenic SPF and a lighter-textured moisturiser has resolved persistent comedones for many people where actives alone did not.

On extraction

Professional extraction by an aesthetician or dermatologist can physically clear existing comedones that are close to the surface. It does not prevent new ones forming. If the underlying follicular hyperkeratinisation is not addressed topically, extraction provides temporary clearance, not resolution. It can be a useful intervention in combination with retinoid treatment — clearing the existing backlog while the retinoid addresses future accumulation — but not a standalone solution.

Self-extraction risks spreading follicular contents into the surrounding dermis, triggering the inflammatory response that creates papules and scarring that were not there before.

The timeline and the consistency requirement

Closed comedones take weeks to months to form. They take weeks to months to clear. A retinoid used three evenings a week for two weeks will not produce a visible result. Eight to twelve weeks of consistent use — with realistic expectations about the purging phase — is the minimum evaluation window.

The routine that addresses closed comedones is not complicated: consistent retinoid use, a salicylic acid exfoliant two to three evenings per week on non-retinoid nights, an oil cleanser, and a non-comedogenic moisturiser. The ingredients are well understood. The main variable is patience.