The Most Hydrating Ingredients Found in Skincare Products

No matter how many times you change your routine or the products you use, one step remains constant. And that is skin hydration. Hydration is crucial for your skin’s suppleness, bounciness, and elasticity, and for the proper function of your skin. Not to mention for the proper glow of your skin. To keep the juices flowing, I’ve put together the best hydrating skincare ingredients.

First things first. Hydration equals water. Quite literally! To properly hydrate your skin, you need water. And for an ingredient to hydrate your skin, it needs to provide water to the skin.

But there’s a thin line between hydration and moisture. And there are some overlapping aspects, which is why hydrating is sometimes mistakenly used interchangeably with moisturizing.

Because there are two ways you can hydrate your skin. You can hydrate by providing water or you can hydrate by preventing the loss of water (1).

The first option requires the ingredients listed below. The second option requires emollients and/or occlusives, a.k.a moisturizers. Put a pin on that for now.

The best hydrating skincare ingredients are humectants. Humectants is the umbrella term used for ingredients that increase the water content of the skin (2).

How do humectants add water to the skin? Humectants attract water from the deeper layers of the skin to the outer layer.

It’s like a self-sustaining system. But they also attract water from the air and bind it to the skin provided that the humidity is around 70%.

Creams that are heavily humectant-based tend to be lightweight and gel-like. Whether you have dry skin or oily skin, you need hydration.

For that, below are the most hydrating skincare ingredients to replenish the skin. Look for them in your cleansers, serums, toners, and moisturizers.

1. Glycerin/Glycerol

Glycerin, a compound that’s naturally found in your body, is the most common humectant found in skincare products. It is so common that we don’t even think of it as something important. But remember, before there was hyaluronic acid, there was glycerin.

In skincare products, glycerin is derived from plants. And as a humectant, it’s one of the most effective water-binding substances. But glycerin isn’t something expensive or rare. It’s present in almost all skincare products.

So there’s no need to go out of your way to find a glycerin product to collect the benefits. It’s usually right on top of your ingredient list. When you see that, know that it’s there to hydrate.

2. Hyaluronic Acid

One of the buzziest skincare ingredients out there is hyaluronic acid. Also knowns as sodium hyaluronate, hyaluronic acid is widely known for its ability to hold 1000 times its weight in water.

Because of that, hyaluronic acid plumps up the skin like no other. Think of a dry sponge and a wet sponge. Hyaluronic acid, for the lack of a better word, causes swelling on the skin just like water swells up a sponge.

This action temporarily reduces the appearance of wrinkles and fine lines. It works instantly! As we age, we produce hyaluronic acid less. That’s why hyaluronic acid is also the best hydrating ingredient for aging skin.

Hyaluronic acid is also present in your body and on your skin. So it’s tolerable for all skin types including sensitive skin. You’ll come across products with different molecular weights or cross-linked hyaluronic acid.

This is for making hyaluronic acid more penetrative so that you get the best results. It’s an amazingly hydrating skincare ingredient that all skin types -dry, normal, sensitive, oily- will benefit from.

Look for hyaluronic acid in all your skincare products especially if you have dehydrated skin. Try hyaluronic acid moisturizers to hydrate and moisturize your skin. And try hyaluronic acid serums when you want to boost hydration.

3. Lactic Acid/Sodium Lactate

Lactic acid is part of the skin’s natural moisturizing factors (3). It’s a naturally-occurring acid. In skincare products, it’s usually derived from milk.

You might be more familiar with lactic acid in the context of chemical exfoliants. Lactic acid is an alpha-hydroxy acid that exfoliates the top layer of the skin and removes the dead skin cells from the surface.

But among all alpha-hydroxy acids, lactic acid has a unique ability to work as a humectant as well. To get the most out of its hydrating abilities, use lactic acid serums in low concentrations.

That way, you exfoliate very gently but also rehydrate your skin. This is also why lactic acid is commonly recommended for people who are dealing with dryness and dehydration. You can also consider using a lactic acid cleanser for gentle, non-drying exfoliation.

4. PCA

Short for pyrrolidone carboxylic acid, PCA is also among your skin’s natural moisturizing factors (NMF). It can also show up on your products as sodium PCA.

Unlike hyaluronic acid, which can make a skincare product alone, you barely come across sodium PCA as a standalone serum or cream.

But the more the humectants, the merrier. That’s why most hydrating serums combine hyaluronic acid with other humectants like sodium PCA.

5. Urea

Another naturally-occurring compound, urea is also a humectant found in moisturizers. It’s been widely used to treat dry, flaky skin. But urea is not just a humectant; it’s also an exfoliant.

For it to hydrate, it needs to be in low concentrations (4). But no worries. In moisturizers, urea is formulated accordingly so that it hydrates and does not impart other effects.

6. Honey

Honey is widely used in DIY face masks and lip masks. And there’s a good reason for that. Honey is incredibly rich in vitamins, amino acids, sugars, and minerals. It’s anti-bacterial, nourishing, hydrating, and softening for the skin.

Some of the amino acids found in honey are also found in the skin’s NMF. That’s why it’s hydrating for the skin. Also, the sugars found in honey work as humectants by binding water to the skin (5).

7. Polyglutamic Acid

And speaking of amino acids, polyglutamic acid is another hydrating skincare ingredient that works very well for all skin types.

Because polyglutamic acid is a combination of a recurring amino acid, namely glutamic acid. It’s a humectant so it attracts water to the skin. But it also helps the skin retain that water.

Because of its structure, it creates a very thin layer on the skin to prevent water loss. So it works double duty to replenish the skin. That’s why products with polyglutamic acid are majorly hydrating and also moisturizing.

8. Panthenol

Also called pro-vitamin B5, panthenol is another common humectant found in hydrating skincare products. When used topically, panthenol converts to the active form of vitamin B5, which is pantothenic acid (6).

What sets it apart from other humectants is its ability to calm and soothe the skin. That’s why panthenol is majorly formulated in soothing products or barrier-repairing products.

It’s the ideal tool for people with dry, sensitive skin. It’s also the best ingredient to use when you’ve over-exfoliated or dealing with rosacea flares.

As you can see, most of these hydrating ingredients are naturally occurring. So essentially, skincare products that aim to mimic your skin’s natural moisturizing factors make the best hydrators for the skin.

These ingredients are super hydrating for dry skin. But they’re great for oily skin as well. Because humectants are water-based. So they are non-comedogenic.

Even though glycerin, hyaluronic acid, lactic acid, PCA, and urea are the best skincare ingredients for hydrating your skin, they’re not the only humectants.

Amino acids like l-serine, arginine, and glycine are also used in skincare products to hydrate, enhance moisture, and support the skin barrier. Some emollients like squalane and ceramides can also double as humectants.

How Do You Hydrate and Moisturize?

So we’ve established how you hydrate your skin. You use humectants. But providing water is not enough. Because our skin constantly loses water.

This phenomenon is called transepidermal water loss a.k.a dehydration. To prevent dehydration, you need an emollient or an occlusive. They lock that water in and put a lid on the skin, so to speak.

They can be anything from shea butter to avocado oil. A good moisturizer contains both humectants and emollients. And depending on your skin type, it can contain occlusives as well.

To learn more about how emollients and occlusives work, remember to check out our guide on different types of moisturizers to find the best one for your skin.

References:

1. Baran, R., & Maibach, H. (2017). Skin Care Products For Normal, Dry, and Greasy Skin [E-book]. In Textbook of Cosmetic Dermatology (5th ed., p. 168). CRC Press. https://doi.org/10.1201/9781315160504
2. Sethi, A., Kaur, T., Malhotra, S. K., & Gambhir, M. L. (2016). Moisturizers: The Slippery Road. Indian journal of dermatology, 61(3), 279–287. https://doi.org/10.4103/0019-5154.182427
3. Farage, M. A., Miller, K. W., & Maibach, H. (2010). Natural Moisturizing Factor (NMF) [E-book]. In Textbook of Aging Skin (2010th ed., pp. 931–935). Springer. https://doi.org/10.1007/978-3-662-47398-6
4. Celleno, L. Topical urea in skincare: A review. Dermatologic Therapy. 2018; 31:e12690. https://doi.org/10.1111/dth.12690
5. Burlando, B., & Cornara, L. (2013). Honey in dermatology and skin care: a review. Journal of cosmetic dermatology, 12(4), 306–313. https://doi.org/10.1111/jocd.12058
6. Cho, Y. S., Kim, H. O., Woo, S. M., & Lee, D. H. (2022). Use of Dexpanthenol for Atopic Dermatitis-Benefits and Recommendations Based on Current Evidence. Journal of clinical medicine, 11(14), 3943. https://doi.org/10.3390/jcm11143943