Serums & ampoules

The serum is the step where you target: it is the most concentrated product of the routine, the one that treats a specific concern rather than maintaining the whole.

The ampoule, a Korean speciality, is more concentrated still — you use it as a cure over a few weeks, during a period when the skin needs a push, rather than continuously.

One piece of advice that saves a lot of irritation: one active serum per time of day. Vitamin C in the morning, retinal at night, never both together when you are starting out.