The Best Hydrating Serums for Dry Skin, From Boots to Space NK

They're not the same. Dry skin is a skin type: it makes too little oil and tends to flake. Dehydrated skin is a condition: it lacks water, and even oily skin can have it. Dry skin needs oils and ceramides. Dehydrated skin needs water-binding ingredients like hyaluronic acid and glycerin. Most people in a British winter need both.

A quick test: pinch your cheek gently. If it wrinkles finely like crepe paper rather than bouncing back, it's dehydrated. If it's rough and flaky but not tight, it's dry.

Hyaluronic acid. Holds many times its weight in water. Look for several molecular weights on the label so it works at different depths.

Glycerin. Unglamorous, cheap and brilliant. Often does more than the fancy ingredients.

Ceramides. Rebuild the barrier so the water you add stays put.

Squalane. A lightweight oil that mimics skin's own. Ideal for dry skin that hates heavy creams.

Panthenol. Vitamin B5. Soothes redness and flaking, especially around the nose.

Under a tenner. The Ordinary Hyaluronic Acid 2% + B5 at Boots is the one beauty editors still recommend, mostly because it works. CeraVe is the choice if your skin is also sensitive. Mid-price. La Roche-Posay Hyalu B5 from Lookfantastic is calming and plumping in one. Cult Beauty has strong options from Medik8 and Dr. Dennis Gross. The splurge. Dr. Barbara Sturm's Hyaluronic Serum at Space NK is the cult favourite. Selfridges and Net-a-Porter also stock Augustinus Bader and SkinCeuticals, if you'd rather spend once and properly.

Apply hyaluronic acid to damp skin, never bone dry. In a dry room it can pull water out of your skin instead of the air. Then seal it in straight away with a moisturiser. In the morning, finish with SPF. At night, a few drops of facial oil on top makes a real difference by morning.

Swap a foaming cleanser for a cream or balm one, keep showers lukewarm and put a bowl of water or a humidifier by the radiator. A serum can only do so much if everything else is stripping your skin.

Persistent flaking, itching or redness may be eczema or dermatitis rather than plain dryness, and is worth a chat with your GP or a pharmacist. Expensive doesn't always mean more hydrating, as the budget picks above prove. And while you're at it, don't forget your hands. See our hand serum heroes.