Three products have solid evidence behind them: a cleanser that doesn't strip, a moisturiser, and sunscreen. Everything past that is optional, and past about five products the additions start working against each other. This is an unpopular thing to publish on a site that links to products, which is roughly why it's worth publishing.

Where the long routine came from

The multi-step routine entered Western retail around 2014 as an adaptation of Korean beauty practice, and it was adapted by retailers before it was evaluated by anyone else. A ten-step sequence is an excellent merchandising structure: it defines ten shelf positions, ten repeat purchases, and a natural upgrade path. That doesn't make it wrong. It does mean the structure was not derived from evidence about how many products skin benefits from, and nobody has since produced that evidence.

The overlap problem

Count the jobs a routine can do. Cleanse. Hydrate. Occlude. Protect from UV. Deliver one or more actives. That's five, and a well-chosen product does two or three of them at once.

An essence, a hydrating toner, a hydrating serum, and an ampoule are, in most cases, four humectant solutions applied in sequence. The stratum corneum holds a finite amount of water. The fourth application is not reaching a compartment the first three missed.

The interaction problem

Every added product raises the probability of irritation, both because the ingredient count rises and because more actives means more chance of a combination that shouldn't be layered. It also increases contact time — a nine-step routine keeps something on your face continuously.

This is not theoretical. The most common self-inflicted barrier damage comes from routines that are individually sensible and collectively too much: an acid toner, a retinoid, a vitamin C serum, and a scrub, each defensible, each doing part of the same job.

The attribution problem

The one that bothers us most. With nine products, you cannot know which one is working. When your skin improves, you'll credit the newest and most expensive thing, because that's how people work. When it gets worse, you'll have nine suspects and no way to test them except by removing things one at a time over two months.

A short routine is diagnostically legible. You can change one variable and observe the result. This is worth more over a lifetime than any individual product in the long version.

What the extra steps do buy

Something worth naming honestly: they're pleasant. A layered routine is a ritual, it takes fifteen minutes at the end of a day, the textures are nice, and it functions as a reliable small pleasure. That is a legitimate reason to do it and we're not interested in sneering at it.

It just isn't efficacy, and it should be priced accordingly. If you enjoy the ritual, the ritual is what you're buying, and a five-dollar product performs the ritual as well as an eighty-dollar one.