What Is Hyaluronic Acid, Exactly?

In our endless search for products that promise to diminish fine lines and hydrate skin, there's one ingredient we constantly come across: hyaluronic acid. Found in everything from sheet masks to face creams to serums, it's clear that hyaluronic acid wields some serious skincare benefits — but what are they, exactly? We spoke with Dr. Lian Mack, certified dermatologist and founder of GlamDerm, to find out.

Keep reading for our expert-approved guide to hylaruronic acid.

What Is Hyaluronic Acid?

Hyaluronic acid is a type of molecule that is naturally produced in our bodies. The substance is found in many areas including the skin, eyes, and joints. Its primary function is to trap water inside tissue cells, keeping the eyes moist, the joints lubricated, and helping to retain water within the skin.

"Hyaluronic acid is widely used in skincare as a humectant, [a substance that helps the skin hold onto water] and can often be found as the key ingredient in serums, oral supplements, dermal fillers, and eye drops," Dr. Mack tells us. "It is used in many topical formulations, primarily for its hydrating properties to plump and smooth the skin."

What Are the Benefits of Using Products that Contain Hyaluronic Acid?

As we age, the production of hyaluronic acid in the skin tends to decrease. As a result, wrinkles and fine lines become more prominent, as the skin loses volume, hydration, and plumpness. "Hyaluronic acid found in moisturizers and serums can help to reduce wrinkles and fine lines by creating a barrier that retains water in the skin," explains Dr. Mack. "Since it is a naturally occurring substance, it is well tolerated by all skin types and is non-irritating. Unlike other topicals, it is readily absorbed into the skin."

Sounds too good to be true right? Wrong. A study found that its participants experienced significant improvement in skin hydration and wrinkle depth reduction two weeks after using topical nano-hyaluronic acid.

But beyond topical skincare, if you're looking for immediately plumper-looking skin or a more pronounced pout, hyaluronic acid fillers are the answer. These fillers are typically provided by a dermatologist and help to add volume, reduce the appearance of facial folds, instantly create structure, and provide a fuller-looking appearance.

However, the skin is not the only area that can benefit from hyaluronic acid. According to Dr. Mack, the joints can see positive results too. In patients with osteoarthritis, the level of natural hyaluronic acid found in the affected joints tends to break down, which contributes to joint pain and stiffness. Hyaluronic acid injections have proved to be beneficial in these circumstances, with many doctors administering them to relieve patients from pain and lubricate the joints.

Is Hyaluronic Acid Safe to Use?

As frightening as applying a substance with the word "acid" might sound, you'll be pleased to know that when applied topically, there are generally no known side effects. "In my opinion, hyaluronic acid is safe for all skin types including pregnant and breastfeeding women," says Dr. Mack. "It's one of my favorite molecules because it is even suitable for patients with extremely sensitive skin." However, when used in the context of a filler, side effects can include infection, bruising, swelling, and pain, she adds.

Are There Other Names for Hyaluronic Acid?

Hyaluronic acid has a few names, so, if you're looking at the ingredients in your face cream and can't find it, don't be dismayed. The synthesized stuff in skincare products is usually called hydrolyzed hyaluronic acid or sodium hyaluronate (the salt derived from hyaluronic acid). You might also see it referred to as hyaluronan. Since the ingredient has taken over the beauty space, hyaluronic acid or HA is used as an umbrella term for the natural, topical, and injectable substance.

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Where Does Hyaluronic Acid in Skincare Products Come From?

Since hyaluronic acid is naturally found in human tissues, you might be wondering how the ingredient is created for skincare — don't worry, it's not extracted from a human. There are two main sources: plants and animals.

Plant-based hyaluronic acid is extracted from microbial fermentation. This bacterial strain naturally contains hyaluronic acid and is then fermented to yield the desired molecular weights ideal for skincare purposes.

Animal-based hyaluronic acid utilizes the combs of roosters — this is the red flesh at the top of a rooster's head. Like humans, animals also produce hyaluronic acid in their bodies, and the rooster's comb is considered one of the best animal sources.

Most natural, organic, and vegan skincare lines utilize plant-based hyaluronic acid in their formulations, but animal-based hyaluronic acid is still commonly used in supplements and injections.

Can You Increase Your Natural Hyaluronic Acid Production?

As great as products containing hyaluronic acid can be, you might be thinking, "If I already have hyaluronic acid in my body, can't I just produce more?" The answer is yes, if you want to increase your natural hyaluronic acid production, there are several foods that contain the compound or help its production. These include bone broth, soy-based foods, leafy greens, root vegetables, and citrus fruits.