Hydrating serum

Hyaluronic acid in two weights: the larger one stays on the surface and smooths it, the smaller one sinks in and holds water where the skin feels dry by noon. A little panthenol calms the redness that comes with cold wind and central heating.

Two drops on a damp face, pressed in with the palms rather than rubbed, then the day cream on top to seal it. It also goes well under make-up and does not pill. Morning and evening, all year round.

Water-light, unscented, in a frosted glass bottle with a dropper. 30 ml lasts about six weeks, 50 ml about two and a half months.