What’s the Difference Between Hydrating and Moisturizing?

Though often used interchangeably, hydration and moisturization are, in fact, two completely different things. Even more confusing, dehydration and dryness tend to present similarly, with symptoms like rough skin and emphasized fine lines and wrinkles. And the cherry on top of the already-complicated sundae: A lot of hydrating ingredients happen to also be moisturizing, and vice versa. So what’s the real difference between the two? And why are they so important? Read on for everything you need to know about the difference between hydrating and moisturizing, according to board-certified dermatologists Dr. Alicia Barba and Dr. Karan Lal.

Skin Hydration

Skin hydration refers to the absorption of moisture from the air or dermis that infuses your cells with water, says Dr. Barba. Dehydrated skin is void of water, according to Dr. Lal, and needs to be replenished in order to rehydrate.

“There are tons of factors that play into skin hydration,” explains Dr. Barbara, “from getting enough sleep at night, drinking enough water, limiting long exposure to water while showering, using lukewarm water instead of hot water and using gentle skincare products to avoiding over exfoliation (which can rub off natural moisturizers produced by your skin).”

Why It's Important to Keep Your Skin Hydrated

Skin hydration is important for the health and proper functioning of skin cells, but it’s also important for aesthetics. Without proper hydration, skin can look lusterless and crepey. And, fine lines and wrinkles are more prominent, says Dr. Lal. Hydration helps keep skin looking smooth and feeling soft.

Signs Your Skin Is Dehydrated

Dullness

Dehydrated skin appears lackluster and dull, and is generally deficient in radiance and the ability to reflect light well. Dehydrated skin can also sometimes appear flaky and itchy, which makes it more difficult to distinguish from dry skin.

Shadow-y and Sallowness

According to Dr. Barba, dehydration can cause shadows and sallowness around the face. Often, the eyes appear more sunken into the face than normal and have dark circles around them.

Emphasized Fine Lines and Wrinkles

Dehydrated skin tends to have a crepey texture to it, says Dr. Lal. And, fine lines and wrinkles look far more prominent and harsh when skin is dehydrated. This increases visual signs of aging and can be difficult to cover up with makeup.

How to Hydrate Your Skin

When it comes to hydration, you can’t simply splash water on your face and hope for the best. Instead, our experts suggest focusing on nourishing, hydrating skincare ingredients.

Both Dr. Barba and Dr. Lal are fans of hyaluronic acid when it comes to hydrating skin. The gel-like molecule holds water and helps keep skin plump and hydrated by helping the skin retain water.

Polyglutamic acid (PGA) is another go-to hydrator for Dr. Lal. Though less popular in traditional skincare, polyglutamic acid holds four times more moisture than hyaluronic acid. The water-soluble polypeptide is a hydration powerhouse, pulling moisture from the air to hydrate the skin’s surface and the layers beneath it while also locking in moisture.

Ceramides are also great hydrators, according to Dr. Barba. Nearly 50% of the skin lipids that form the natural skin barrier are actually ceramides, which act as glue to hold skin cells together and seal in moisture and hydration. When the skin barrier is compromised, skin becomes dehydrated. By restoring lost lipids, you can likely increase skin hydration.

Interestingly enough, Dr. Barba points to lactic acid as a great skin hydrator. Though the ingredient is technically an exfoliator, its unique structure also allows it to bind water within the skin. And because it’s one of the more gentle exfoliators, it’s less likely to disrupt the skin barrier and cause dehydration.

Skin Moisture

The outermost layer of skin, called the epidermis, is covered with a thin film layer of water and lipids. “Skin moisture is composed of those lipids and water,” explains Dr. Lal. “We lose moisture throughout the day and replenishing that moisture is essential for maintaining a healthy skin barrier.” Without the right balance of moisture, the skin cannot act as the body’s protective barrier. The key here is that moisture helps prevent water from escaping the skin.

Why It's Important to Keep Your Skin Moisturized

Moisturized skin can more easily repair itself than dry skin, which is especially important in the face, neck and chest areas since they’re so sensitive to environmental changes. It’ll also help that skin appear younger, as the daily loss of skin cells leaves these areas vulnerable to fine lines and wrinkles. Moisturization also reduces the chances of both extreme dryness and oiliness.

Perhaps most importantly, moisturized skin helps the skin barrier remain strong and healthy, keeping hydration in the skin and pollutants and other irritants out, says Dr. Barba.

Signs Your Skin Is Dry

Tightness and Rough Texture

When skin becomes excessively dry, it can feel tight and have a rough texture to it, says Dr. Barba. This can also make the skin feel itchy and uncomfortable. Especially dry skin can result in near constant itchiness.

Flakiness, Peeling, Scaling and/or Cracks

As we know, the outermost layer of skin continually renews itself and sheds dead skin cells. We don’t usually see this shedding, but if skin is too dry, it can start to peel off during this shedding process. Likewise, as skin dries out and shrinks, it may develop cracks and flakes, according to Dr. Lal. If deep enough, some cracks may even cause bleeding. 

Emphasized Fine Lines and Wrinkles

Because dry skin has lost moisture and water, it may start to show signs of dehydration too. In particular, Dr. Barba notes emphasized fine
lines and wrinkles.

How to Moisturize Your Skin

Dr. Barba suggests looking for water-based ingredients that grab and, more importantly, hold onto moisture. Both experts are fans of glycerin, a humectant that pulls moisture from the air and draws it to the deeper layers of the dermis to replenish lost moisture. It’s commonly found in moisturizers (because it so effectively, well, moisturizes), and helps keep skin soft and supple.

Petrolatum is another great moisturizing ingredient, according to Dr. Lal. Sometimes called petroleum jelly, the emollient has long been considered one of the most effective moisturizers thanks to its ability to prevent moisture loss. It provides immediate occlusion, making it particularly great for compromised skin, by creating a physical barrier that prevents moisture from leaving the skin.

And, interestingly enough, both dermatologists note some overlap when it comes to hydrating and moisturizing ingredients. Ceramides and hyaluronic acid, for example, both attract water to the skin and subsequently help keep moisture within the skin.

Hydrating vs. Moisturizing: What's the Difference?

Both hydration and moisturization are absolutely key to maintaining the skin barrier. And while there’s certainly a lot of overlap between the two, Dr. Barba offers a keen distinction: “Hydrating ingredients attract water to the outermost layer of the skin, while moisturizing ingredients provide a layer to prevent water from escaping.” Dr. Lal agrees, adding that hydration refers to water content in the skin, whereas moisturization refers to the lipids in our skin (which keep water from escaping the skin).

Best Hydrating and Moisturizing Products

CeraVe Healing Ointment

Packed with ceramides, hyaluronic acid and petrolatum, the CeraVe Healing Ointment offers long-lasting moisture in a non-irritating, gentle formula. By forming a protective layer on top of the skin, the ointment temporarily protects and relieves chapped, cracked skin. It can also be used as the final step in your hydrating skincare routine to help lock in water and moisture overnight.