Hydration is the word skincare uses most and explains least. It is worth understanding, because it decides what a moisturiser can reasonably be expected to do.
Water arrives from the inside
The water in your skin comes from within — from the blood supply, up through the lower layers, into the outer one. A cream contributes a little of its own, but most of what it does is change how much of that water leaves again. Skin loses water to the air constantly, and how quickly depends on the condition of its outer layer.
That layer is the barrier: the outermost cells of the skin and the oils packed between them. In good order it holds water in. When it is thin, dry, or stripped by something harsh, it holds less, and skin feels tight within an hour of washing.
Dry and dehydrated are not the same
Dry skin is short of oil. It tends to be a lifelong type, and it often runs in the family. Dehydrated skin is short of water — a condition rather than a type, which comes and goes with the season, the weather, how you cleanse, and how you slept.
Mature skin is commonly both at once, which is why a light hydrating serum can feel as though it is doing nothing. It supplies water to a barrier that cannot hold on to it.
Hydration is less about what you add than about what you stop losing.
What makes the most difference
- Shorter, cooler showers. Hot water removes the oils that keep water in.
- A cleanser that leaves skin comfortable rather than tight.
- Applying your cream while skin is still slightly damp.
- Indoor heating in winter, which draws water out of skin all day. A humidifier in the bedroom does more than most products.
- Time. The outer layer renews itself over weeks, so give any change a month before judging it.
Not one of those is exciting, and together they matter more than the choice between two good creams.
This article is general information, not medical advice. Speak with a qualified healthcare professional about your own skin, and do not use retinol during pregnancy or nursing without their guidance.
