A hydrating serum is a light facial product with a high share of humectants, such as hyaluronic acid, that gives the skin water and makes it look visibly plumper and softer. In our range of facial serums you will find, for example, the HYA CICA serum, and our Advisor can help you choose.
What a hydrating serum is and what to look for in it
A hydrating serum differs from other facial products in its high concentration of humectants, substances that attract and bind water molecules. The best known humectants include hyaluronic acid, glycerin and panthenol, and each of them works a little differently, which is why a good serum often combines them. Glycerin is a small molecule that attracts water easily and reliably, hyaluronic acid can also hold water near the surface of the skin in a kind of soft water cushion, and panthenol has a soothing effect, so skin looks more even after using it. This very combination makes a hydrating serum a product that suits almost every skin type, because it does not weigh the skin down with fat, it only gives it the water that the skin most often reaches for first.
The texture of a hydrating serum is usually much lighter than that of a cream, mostly a gel or slightly runny consistency that absorbs in a few seconds and leaves no greasy film on the skin. That is why it also suits wearing under make-up or under sunscreen during the day, as well as in an evening routine before the night cream. The smaller humectant molecules can penetrate a little deeper into the skin than most cream ingredients, while the cream then forms a thin layer on the surface that keeps the water in the skin. Serum and cream therefore complement each other, they do not replace each other: the serum brings water to where a cream cannot reach on its own, and the cream in turn keeps it in place for longer. When choosing, it is worth checking the ingredient list on the pack, not just the word serum on the label.
How hyaluronic acid works in a serum
Hyaluronic acid is among the most researched humectants in cosmetics, and its effect in a serum depends mainly on the size of the molecule. Low molecular weight hyaluronic acid can penetrate into the deeper layers of the skin and hydrate it from within, while the high molecular weight version stays more on the surface, where it forms a delicate, breathable film and slows down the evaporation of water. A good serum therefore often combines both types at once, exactly as our HYA CICA serum does, which contains 1% low molecular weight and 1% high molecular weight hyaluronic acid in its composition. The mechanism by which humectants attract and bind water on the skin is also described by studies on humectants and skin hydration available in the PubMed database. If you are interested in hyaluronic acid in more detail, you will find more in a separate article on this ingredient.
How to apply a hydrating serum to damp skin
By their nature humectants attract water from their surroundings, so they work best when they have something to draw on. If you apply a hydrating serum to completely dry skin in dry air, the molecule may start to borrow water from the deeper layers of the skin instead of from the surface, which is exactly the opposite of what you expect from a serum. That is why it is recommended to apply it to slightly damp skin, for example straight after washing your face or after toning, when a little moisture from the water or toner still remains on the skin. Then spread the serum with gentle patting of your palms, let it absorb for a moment and only then continue with a cream, which seals the water you have gained into the skin. This step takes just a few seconds more, but the difference in how your skin feels is noticeable, especially in the drier months of the year.
- Wash your face or tone it, and leave the skin slightly damp.
- Take a small amount of serum and spread it by patting with your palms.
- Wait about half a minute for the serum to absorb.
- Continue with a cream that seals the water into the skin.
What is the difference between a serum and a cream?
A serum and a cream are not rivals, they simply solve a slightly different task and work best together, not instead of each other. A hydrating serum has a light, mostly gel texture, and its main job is to bring water to the skin thanks to a high share of humectants such as hyaluronic acid or glycerin. A cream, by contrast, is thicker and contains more oils and so-called occlusive ingredients, which form a thin layer on the skin surface and prevent the water from evaporating again. That is why you always apply the serum before the cream, never the other way round, since the order decides whether the active ingredients get where they should. If you have oilier skin, a serum alone without a cream may sometimes be enough for the day, while drier skin usually cannot do without the sealing layer of a day cream.
| Feature | Hydrating serum | Cream |
|---|---|---|
| Texture | Light, gel | Thicker, creamy |
| Main job | Bringing water (humectant) | Sealing in water (occlusive) |
| Order in the routine | After toning, before the cream | As the last step |
| When it is enough on its own | Oilier skin during the day | Drier skin almost always |
A simple hydrating routine with a serum
A hydrating routine with a serum does not have to be complicated; it just needs the right order and a little regularity. Morning and evening, start with gentle cleansing, continue with a toner and apply the hydrating serum to slightly damp skin. Try, for example, the HYA CICA serum with low and high molecular weight hyaluronic acid, which suits an everyday routine, or the Hydrating peptide serum, which besides glycerin and hyaluronic acid also contains rose water and plant extracts. Finish the routine with a cream, according to the texture your skin likes right now: lighter during the day, richer at night. If you are not sure which serum will suit you best, let our Advisor guide you right on the website, or try both serums alternately and watch how your skin reacts to them.
- Morning: gentle cleansing, toner, serum, light cream.
- Evening: gentle cleansing, toner, serum, richer cream.
- Once every few days: a mask or more intensive care, as your skin needs.
Did you know…
Did you know that a hydrating serum works best on slightly damp skin, because humectants need something to draw water from?