Chemistry doesn’t negotiate

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People combine products. Not out of foolishness — out of logic. If one product is good, two are better. If AHA exfoliates and retinol renews, both together are doubly effective.

Chemistry doesn’t negotiate.

Take the first pair… benzoyl peroxide in the morning and retinol at night. The logic: benzoyl peroxide kills bacteria, retinol renews cells, attack acne from two sides. But the chemistry: benzoyl peroxide generates free radicals. Retinol makes the skin thin and light-sensitive. Together they break down the lipid barrier faster than the skin can repair it. Water loss rises. The skin turns reactive — red, flaky, burning. And both products trigger sebum rebound when you stop. That’s not two solutions. It’s two stressors.

The second pair… AHA and BHA daily. The logic: AHA exfoliates the surface, BHA exfoliates inside the pores, total coverage. But the chemistry: both are acids. Both dissolve the bonds between skin cells. Daily use removes cells faster than the skin can replace them. The stratum corneum — the outermost layer that holds moisture in — gradually gets thinner. The skin becomes oversensitive, red, tight. Dermatologists recommend a maximum of two to three times a week for each. Most product labels say daily.

The third… a cleanser with SLS and a moisturizer with hyaluron. The logic: thorough cleansing and deep moisture, the perfect pair. But the chemistry: SLS strips the barrier. The skin loses ceramides and lipids. Hyaluronic acid binds water — but it binds it from its surroundings. In dry air it pulls water up from deeper skin layers instead of from the air. So SLS removes the lipid barrier, and hyaluron pulls the moisture out of the skin that was just exposed. One product damages. The other worsens the consequence. And both sit in the recommended “morning routine.”

And then there’s the idea that more active ingredients give a better result. The logic: vitamin C protects, niacinamide strengthens the barrier, retinol renews — use them all. Three actives, three benefits. But the chemistry: each active has its own optimal pH. Vitamin C needs a pH below 3.5 to penetrate. Niacinamide works best at pH 5 to 7. Retinol is pH-sensitive and breaks down in an acidic environment. Stacking them on top of each other means at least one of them is working under suboptimal conditions. And each layer is one more burden on a barrier that may already be thin.

And then the ten-step routine. The logic: more coverage, more actives, better results. But the chemistry: each product’s pH, surfactants, and actives interact with the others. Oil cleanser, foam cleanser, toner, essence, serum, ampoule, sheet mask, eye cream, moisturizer, sunscreen. Each layer changes the skin’s pH. Each active competes for receptors. Each surfactant removes a little of the previous layer. And ten layers on skin that normally manages on its own with sebum and sweat — that’s not care. It’s overstimulation.

Cosmetic intolerance syndrome. Skin that has become allergic to everything because it’s been given too much of everything. Dermatologists see it more and more often.

And then there’s that sentence… “natural oils clog pores.” You’ve heard it. Maybe from a dermatologist. Maybe from an influencer with a ring light and a sponsored serum. And it’s based on a scale from 1979 that was tested on rabbit ears.

Rabbit ears. Not human faces. Rabbit ears.

Albert Kligman smeared pure ingredients — 100 percent concentration — on the inside of rabbit ears and counted comedones. The results became the comedogenic scale, from 0 to 5, that still circulates on blogs and in YouTube videos as if it were science.

The problem: rabbit ears are far more sensitive than human skin. The researchers didn’t even realize that rabbit ears have naturally enlarged pores — some results counted those as comedones. Same substance, different labs, different scores.

In 2006, dermatologist Zoe Diana Draelos published a re-evaluation. Her conclusion: finished products with “comedogenic” ingredients aren’t necessarily comedogenic. The blend changes everything. The concentration changes everything.

In 2025 a full review confirmed it… there’s no standardized test method. There’s no regulation. Companies are free to write “non-comedogenic” on the label — with no test, no proof, no consequence.

Coconut oil scores 4 on the rabbit-ear scale. Shea butter scores 0. Mineral oil scores 0 to 1 — and reduces water loss by 99 percent. “Mineral oil clogs pores” is a myth. It’s one of the best-documented occlusives in dermatology.

And soap? Soap is wash-off. It’s on the skin for seconds. Comedogenicity tests run with occlusion for hours to days. Saying “coconut oil clogs pores, therefore soap with coconut oil is comedogenic” is like saying “flour contains gluten, therefore bread baked with flour is still raw dough.”

During saponification, the fatty acids are turned into soap salts. The original oil no longer exists.

And the pattern — again. It’s the same as in the hair series. Each product creates the need for the next. SLS cleanser requires moisturizer. Exfoliation requires repair cream. Retinol requires sunscreen, requires a cleanser to remove the sunscreen, requires moisturizer because the cleanser dried you out.

And on top of it all… a comedogenic scale based on rabbit ears, telling you that natural oils are dangerous — while “non-comedogenic” on a bottle of SLS, fragrance, and silicone means nothing at all.

Each step is logical on its own. Together it’s a carousel.

Two steps work: wash mildly, let the skin do the rest. It sounds too simple. It is too simple. That’s why nobody sells it.

Sources:

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