The Science of Skin Hydration
Many aspects of healthy looking skin rely on optimal moisture levels, so it’s important to keep your skin hydrated. Unfortunately, it isn’t quite as easy as making sure the skin contains enough water; there’s a lot more going on that first meets the eye. Let’s take a look at the science of hydration, how to spot the signs, and how to choose the right ingredients and products for you.
Understanding the Fundamentals of Skin Hydration
Hydration is fundamental to the healthy functioning of skin. When the skin lacks water it negatively affects many processes within that keep it looking smooth, plump and protected. To keep water in and harmful, external elements out, we rely on a protective barrier known as the skin barrier. It’s made of natural, water-loving and oil-loving molecules that work together to maintain optimal water levels.
Humectants: Water-Loving Molecules
While water-loving molecules (known as humectants) are often referred to as little water magnets, they don’t pull water from other areas of the body. We prefer to think of them like sticky tape, as water molecules “stick” or bond to them as they pass by, helping to hold water within the skin. These include molecules such as amino acids, urea and sodium lactate.
Lipids: Oil-Loving Molecules
Alongside humectants, oil-loving molecules known as lipids play a key role in maintaining skin hydration.. Lipids help to trap water inside and stop it from leaving the skin. Ceramides, fatty acids and cholesterol are all types of skin lipids that work alongside humectants to form the skin barrier: humectants hydrate the skin, while lipids moisturize.
Hydration vs. Moisturization: Understanding the Difference
Although they might sound the same, hydration and moisturization actually have distinct differences. When we talk about hydration, we’re talking about increasing the water levels within the skin using humectants like glycerin, hyaluronic acid, urea and beta glucan. Moisturization on the other hand refers to supplying the skin with both hydration (increased water levels) and lipids to help protect water from leaving the skin. Common examples of lipids used in skincare are triglycerides, ceramides and fatty acids. We refer to them as emollients, which is the collective term given to oil-loving molecules that help hold water in to smooth and soften skin.
Skin Thirst: Recognizing the Signs of Skin Dehydration
As we’ve discovered, hydration is fundamental to healthy skin appearance and is, therefore, one of the most important considerations when building your skincare regimen. A common sign of skin dehydration is a tight, uncomfortable feeling. Prolonged dehydration can impact the skin renewal process and lead to dry, flaky skin as well as uneven texture and a dull appearance. Dry skin can then also be more prone to irritation and signs of redness.
It’s common knowledge that dry skin types and areas of dryness in combination skin may be dehydrated, but it’s not limited to this skin type; oily skin can get dehydrated too. Research shows that oily skin types often have lower hydration levels than dry, normal, or combination skin, so it’s important to include hydration in your skincare regimen, regardless of skin type.
Key Ingredients for Optimal Skin Hydration
Now we know the fundamentals of hydration, let’s take a look at some key hydrating ingredients to look for in your products.
Hyaluronic Acid
This is a naturally-occurring molecule found within the skin that helps to attract and hold onto water. It easily bonds with water, making it ideal for helping to hydrate and plump. It can be found in a range of molecular sizes making it great at providing hydration to multiple layers of the skin’s surface.
Pro-Vitamin B5
This ingredient—also known as panthenol—is a humectant (water-loving). It’s commonly used within skincare for its ability to help support multiple elements of skin hydration. Because of its water-loving properties, it’s able to help attract and retain moisture within the skin while also working to support the formation of key barrier components such as ceramides and fatty acids.
Ceramides
These are also naturally occurring molecules found within the top layers of the skin and make up approximately 50% of the skin’s lipids. They help create structures within skin that trap water inside and reduce water loss. They work very effectively in combination with humectants to help keep skin hydrated.
Natural Moisturizing Factors (NMF)
This is a collective name given to a number of molecules found within the surface layers of the skin. You may have heard of urea, amino acids and PCA. These are types of NMF often used within skincare that work as humectants to attract and hold onto water.
Building a Hydrating Skincare Regimen
Replenish & Hydrate - Regimen for Dehydrated Skin
When building your regimen, it can be difficult to know which are the best products for dehydrated skin. Explore how to replenish skin hydration with this regimen for dehydrated skin.
- Glycolipid Cream Cleanser
This cream cleanser helps provide gentle yet effective cleansing and makeup removal. It is non-stripping and designed to respect the skin barrier to maintain hydration. - Hyaluronic Acid 2% + B5 (with Ceramides)
Our newly reformulated Hyaluronic Acid 2% + B5 (with Ceramides) contains five different sizes of hyaluronic acid, vitamin B5, and the new addition of ceramides to help provide multi-layer hydration. It helps to support the skin barrier for more hydrated, plumped skin and now comes in a lighter, non-tacky texture. - Niacinamide 10% + Zinc 1%
Niacinamide 10% + Zinc 1% is a lightweight water-based serum containing niacinamide and zinc PCA. It helps support the skin barrier while helping to target uneven tone and texture, for a smooth, radiant appearance. - Natural Moisturizing Factors + HA
Natural Moisturizing Factors + HA is a mid-weight cream formula, ideal for all skin types. It helps provide delivery of key skin barrier components such as natural moisturizing factors and skin lipids to help support hydration and the skin barrier.
Replenish & Hydrate - Regimen for Dehydrated Skin
When considering what skin care to use for dry skin, it is important to include moisturizing products for dry skin, alongside hydrating products. Explore our nourishing regimen for dry skin.
- Squalane Cleanser
This balm-like cleanser helps to effectively clean the skin of makeup and impurities, while supporting the skin barrier through hydration. It’s non-comedogenic meaning it won’t block or clog the pores of your skin, leaving your skin feeling smooth and soft. It’s also suitable for all skin types. - Hyaluronic Acid 2% + B5 (with Ceramides)
Our newly reformulated Hyaluronic Acid 2% + B5 (with Ceramides) contains five different sizes of hyaluronic acid, vitamin B5, and the new addition of ceramides to help provide multi-layer hydration. It helps to support the skin barrier, for more hydrated, plumped skin. - Niacinamide 10% + Zinc 1%
Niacinamide 10% + Zinc 1% is a lightweight water-based serum containing niacinamide and zinc PCA. It helps support the skin barrier while helping to target uneven tone and texture, for a smooth, radiant appearance. - Natural Moisturizing Factors + PhytoCeramides
Natural Moisturizing Factors + PhytoCeramides is our most nourishing moisturizer, including nearly 4x the level of moisturizing emollients, and 2x the amount of hydrating molecules. Its richer texture makes it ideal for dry skin, helping achieve a fresher, more plumped appearance.
The Key to Hydrated, Radiant Skin
Understanding the science of skin hydration is crucial for maintaining a healthy and radiant complexion. By incorporating the right hydrating ingredients and following a consistent routine, you can effectively combat dehydration and support your skin's natural functions. Explore The Ordinary's range of hydrating products and discover the perfect additions to your skincare regimen.