The cleanser is the most taken-for-granted object on the bathroom shelf. It is also, we have come to believe, one of the most contested categories in modern skin care. We asked six practitioners — one facialist, one formulator, one dermatologist, one cosmetic chemist, one esthetician, and one magazine editor — to define what a cleanser is, fundamentally. We gave them a single sentence prompt. We let them answer at length.
The answers did not overlap.
What follows is a transcription of those conversations, edited for length and ordered by clinical convention rather than chronology.
1. Léa Vidal — Facialist, Marseille
What is a cleanser, fundamentally?
A cleanser is a negotiation. The skin has things on it that you do not want — sebum, particulate matter, the residue of last night’s skincare, the day’s pollution. The cleanser is the substance that removes those things. But the skin also has things on it that you do want — the lipid layer, the natural moisturising factor, the microbiome, the corneocyte adhesion that holds the barrier together. The cleanser is the substance that, ideally, removes only the first set.
The negotiation is the work. The cleanser that removes only what you want removed is, in my practice, the cleanser that works. The cleanser that also removes some of the second set is, by definition, an imperfect cleanser. The imperfect cleanser is, in my practice, almost all of them.
I have been working for twenty-two years. I have not yet found a cleanser that I can describe as perfect. The perfect cleanser would be a substance that distinguishes, at the molecular level, between the sebum on the surface and the lipid in the stratum corneum. The biochemistry for this does not exist. The marketing for it does.
What cleanser do you recommend?
I do not recommend a cleanser. I recommend a cleansing practice. The practice includes the product, but it also includes the water temperature, the cloth, the duration of the massage, the timing in the routine. A perfect cleanser used in the wrong way is worse than an imperfect cleanser used in the right way.
2. Sara Bekele — Formulator, Brooklyn
What is a cleanser, fundamentally?
In formulation, a cleanser is a delivery system for a surfactant. The surfactant is the molecule that does the work — it lowers the surface tension of water, allowing the water to mix with the sebum and lift it off the skin. The formulation around the surfactant is what determines the character of the cleanser: how it feels, how it foams, how it rinses, what it leaves behind.
The surfactant is the cleanser. Everything else is theatre.
What is the industry mistake?
The mistake is to confuse the surfactant with the formulation. A cleanser that contains a very mild surfactant — a sugar-based surfactant, an amino-acid-based surfactant — but is poorly formulated, will be harsh on the skin. A cleanser that contains a stronger surfactant but is well formulated — with the right pH, the right ratio of surfactant to water, the right co-surfactants — will be gentle. The industry talks about mild surfactants. The mildness is in the formulation. The surfactant is, in most cases, secondary.
Anything else?
Stop washing your face twice. Most skin does not need a twice-daily cleanse. The skin, in the morning, has very little on it that needs removing. The twice-daily cleanse is a habit the industry has been trying to install for thirty years, because twice-daily means twice the product. The skin does not benefit. The industry does.
3. Dr. Inès Ferrand — Dermatologist, Paris
What is a cleanser, fundamentally?
A cleanser is a medical category in my practice, but not in the way the marketing suggests. There are cleansers I prescribe — for acne, for rosacea, for perioral dermatitis — and there are cleansers I ask patients to stop using. The cleansers I prescribe are, in most cases, not what the patient is currently using. The cleansers I ask patients to stop using are, in most cases, what they came in using.
A cleanser is, for me, a problem-solver or a problem-creator. It is rarely neither.
What cleanser do you prescribe?
For acne: a benzoyl-peroxide wash, 5%, left on for thirty seconds. For rosacea: a zinc-pyrithione bar, used twice daily. For perioral dermatitis: nothing. No cleanser at all, just lukewarm water, for six weeks.
The cleansers I prescribe are not the cleansers patients want to buy. The cleansers patients want to buy are, in my experience, the cleansers that often create the problem they were meant to solve.
What is the biggest mistake?
Over-cleansing. The skin barrier has a finite amount of ceramide. The cleanser removes some of it every time it is used. The barrier rebuilds. The rate of rebuilding is not infinite. The patient who washes twice daily with a foaming cleanser is, in most cases, slowly outpacing her barrier. The patient does not notice for years. The patient notices when the barrier fails. By then, the pattern is entrenched.
4. Dr. Hana Yamazaki — Cosmetic chemist, Tokyo
What is a cleanser, fundamentally?
A cleanser is a phase. The phase is the mixture of water, oil, and surfactant that, when applied to the skin, lifts the sebum into a removable form. The phase can be a single phase (an oil cleanser, a micellar water) or a two-phase (a cream cleanser, a balm cleanser). The phase is what determines the mechanism of the cleanse.
A single-phase cleanser lifts the sebum by solvency — the oil dissolves the oil. A two-phase cleanser lifts the sebum by emulsification — the surfactant carries the oil off in the water. The two mechanisms do not feel the same on the skin. The two mechanisms do not, in most cases, leave the skin in the same state.
What is the formulator’s question?
The formulator’s question is: what does the skin need removed, and by what mechanism? The answer varies by skin type, by climate, by time of day, by the products applied in the previous 24 hours. There is no single right answer. There is, however, a wrong default — the default of a foaming surfactant cleanser twice daily, regardless of skin type. The wrong default is, in my experience, the most common.
What cleanser do you use?
A cleansing oil at night. Nothing in the morning. I have used this routine for fourteen years. My barrier is intact. My patients, in most cases, ask me why their barrier is not.
5. Olivia Chen — Esthetician, Los Angeles
What is a cleanser, fundamentally?
A cleanser is a ritual object. The skin care industry in 2026 has, in my opinion, over-emphasised the chemistry of the cleanser and under-emphasised the use of it. The cleanser is, for most of my clients, the most-used product in the routine. The cleanser is also the product that the client spends the least time thinking about.
The cleanser, as a ritual object, has three parts: the product, the water, and the hands. The product matters. The water matters more — most of my clients wash with water that is too hot. The hands matter most of all — most of my clients wash for less than thirty seconds.
What cleanser do you recommend?
A cleansing milk or a cleansing balm. Applied to dry skin. Massaged for ninety seconds. Removed with a warm, damp cloth. The whole process takes four minutes. The whole process is, in my clients’ lives, a kind of meditation.
What is the most common mistake?
The twenty-second wash. The client applies the cleanser, works up a lather, rinses. The cleanser has, in this twenty-second window, done approximately nothing useful. The surfactant has not had time to engage with the sebum. The sebum has not been lifted. The face has been moistened and rinsed.
The cleanser, in the twenty-second wash, is not a cleanser. It is a wetting agent.
6. Anya Brennan — Beauty editor (retired), London
What is a cleanser, fundamentally?
A cleanser is a decision. The decision is: what kind of clean am I, today, willing to live with? There is the clean of nothing on the skin — the post-cleanse tightness, the slight squeak, the feeling that the face has been reduced to its minimum. There is the clean of something left behind — the soft, slightly conditioned surface of a cream cleanser that has not been fully rinsed. There are, between these two, many cleans.
The decision is, in most cases, made for the editor by the industry. The industry has, in 2026, a strong preference for the first kind of clean — the squeaky clean, the bare face, the nothing-on-the-skin. The second kind of clean has, in the editorial imagination, been demoted to a non-clean, as though the skin, after a cream cleanser, is somehow still dirty.
I disagree. The second kind of clean is, in many cases, the better clean.
What cleanser do you use?
I use, in the morning, nothing. I use, at night, a cleansing oil, followed by a cleansing cream, followed by a cloth. I am, by 2026 standards, an unusual case. I am also, in my own opinion, a well-cleansed one.
What is the industry’s mistake?
The industry’s mistake is the squeak. The squeak is the sound the skin makes when it has been stripped of sebum. The squeak is, in the industry, a sign of clean. The squeak is, in the dermatologist’s office, a sign that the cleanser has done too much.
The squeak is the sound of a barrier that has been washed off. The industry should not be celebrating it.
What we take from this
Six practitioners, six answers. The cleanser is a surfactant delivery system, a ritual object, a medical category, a phase, a negotiation, and a decision. It is, in short, six different products hiding under one word.
We would gently suggest that the next time you read a review of a cleanser, you ask: cleanser, according to whom? The facialist’s cleanser is not the dermatologist’s. The chemist’s is not the esthetician’s. The editor’s is not the formulator’s.
The cleanser, on your shelf, is doing its work without needing you to name the work. But if you wanted to name it, you would do well to choose which practitioner you are listening to.
Six definitions. One shelf. The category is, finally, larger than its word.