Dermalogica Smart Response Serum (£130) promises to address micro-changes in the skin — which could be the result of external damage or self-defence (from over-exposure to UV rays, for example) — before those changes become visible to the naked eye in the form of a wrinkle, dark spot, dry patch, or redness. The serum contains four unique ingredients that the brand says help to soothe (Japanese cornelia cherry), firm (mannose-6 phosphate), brighten (hydrolysed wheat flour), and hydrate (oligosaccharides), in addition to classic skin-care actives like glycerin and niacinamide.