Skincare layering order

1. 1

   Cleanser

   Sunscreen and sebum block everything after it. At night, that's the whole job.
2. 2

   Watery treatment

   Toner, essence or hydrating mist — thin layers can't push through thick ones.
3. 3

   Active serum

   Vitamin C, niacinamide, exfoliating acid or retinoid. Damp skin, not wet.
4. 4

   Moisturiser

   Seals the layers underneath and buffers the sting of anything strong.
5. 5

   Sunscreen (AM)

   Always last, always generous. Nothing goes over it except makeup.

Everything else — eye cream, spot treatment, face oil — slots in by texture. An oil goes after moisturiser because nothing water-based will get through it.

Absorption isn't a race; it's about contact. A watery essence applied over an occlusive cream mostly sits there and evaporates. Reverse the order and both layers do their job.

The second real effect is buffering. Applying a retinoid over moisturiser instead of under it measurably reduces irritation while keeping most of the benefit — the "sandwich method" people talk about, and a legitimate way to stay on a retinoid you'd otherwise abandon.

The third is sunscreen. It's tested as a continuous film at 2 mg/cm². Anything rubbed in over it disturbs that film, which is why it goes last and why reapplication over makeup is a genuinely awkward problem rather than a solved one.

• "Wait 20–30 minutes between steps." Not needed. Waiting until the previous layer isn't visibly wet — under a minute — is enough for almost everything.
• "Never mix niacinamide and vitamin C." Based on a heated-lab-sample study, not on how products behave. The full explanation is here.
• "pH must recover before the next step." Relevant only for high-strength acids, and even then the effect is smaller than the irritation you risk chasing it.
• "More steps means better skin." A ten-step routine mostly increases the odds of irritation and of never knowing which product caused what.

Strong exfoliating acid plus a retinoid on the same night is the most common way people wreck their barrier. Alternate nights instead.

Pilling is a texture clash, not a sign of a bad product: silicone-heavy layers over film-formers like carbomer or certain gums, applied too fast or too thick. Use less, pat rather than rub, give each layer a few seconds, and if it still pills, change the pairing rather than the technique.