Hyaluronic acid is one of the, if not the, buzziest words in skincare. This universally hydrating humectant is capable of binding over 1,000 times its weight in water and is now one of the most notable and sought-after moisturizing ingredients.

Ever wonder how this popular ingredient mixes with others? We spoke with cosmetic chemist Shuting Hu, aesthetic practitioner Linne Linder, and board-certified dermatologist Shari Sperling, MD, to find out. Read on to learn just how hyaluronic acid works with your favorite skincare ingredients.

Hyaluronic acid (HA) is a naturally occurring glycosaminoglycan found throughout the body’s connective tissue. Glycosaminoglycans are simply long unbranched carbohydrates, or sugars, called polysaccharides.

HA is the main component of what gives your skin structure, and is responsible for that plump and hydrated look. You may have heard the chatter around collagen, but hyaluronic acid is where it’s at.

With the buzz around anti-aging, it’s about time we talk about hyaluronic acid, its benefits for our skin, and why molecular weight of an ingredient is important! It plays a pivotal role in the wound healing process, and decreases as we age making us more susceptible to sagging and wrinkles.

What are the benefits of hyaluronic acid?

HA benefits

  • anti-aging
  • moisturizing
  • wound healing
  • anti-wrinkle
  • increases skin elasticity
  • can treat eczema
  • can treat facial rednes

Why’s hyaluronic acid so magical? For starters, HA can bind up to 1000 times its weight in water! In other words, it functions as a humectant and holds water molecules onto the surface of your skin to keep it nice and hydrated.

Anytime we’re talking about skin that’s well-moisturized, we’re mainly referring to skin that has a lot of water content. Perhaps you’ve heard the term transepidermal water loss, or TEWL for short? This is the scientific term for the measurement of how much water is evaporated from the skin.

When a product prevents TEWL, that means it’s keeping your skin hydrated by making sure that water doesn’t escape from your skin’s surface. Hyaluronic acid does exactly that by slowing the rate at which the water evaporates.

Apart from being a very effective hydrator, a couple of studies have also found that it’s very good for healing wounds, too!

Are there side effects to using hyaluronic acid?

If you’re formulating your own products, or purchasing HA products that list the percentage, we recommend keeping the HA concentration below 2 percent. Why?

A very low molecular weight of 5 kDA HA has the ability to penetrate the skin, which means it can potentially carry other unwanted ingredients, chemicals, and bacteria more deeply into the skin. If you have compromised skin, this might be bad news. Thankfully, on its own, HA tends to not cause allergic reactions since our bodies also make it.

Fortunately, cosmetic chemists have this science down, so we can defer to their expertise and what people say about certain HA products. But if you’re formulating your own HA serums, know that not all hyaluronic acid is equal.

This holy grail of hydration may have unintended side effects. There are some varieties of HA that are a bit controversial, and increased levels are actually linked to inflammatory skin diseases like psoriasis.

One study Source found that an application of HA actually slowed down wound healing, compared to just pure glycerin. Yikes! This may have been because of the concentration and molecular weight of the hyaluronic acid.

What’s the science behind hyaluronic acid?
The benefits of hyaluronic acid on the skinhas to do with its molecular weight and concentration. In this case, size matters! The molecular weight refers to its mass, or how big the HA molecule is. This is measured in something called unified atomic mass units — daltons, or kDa for short.

HA between 50 to 1,000 kDa is the most beneficial for skin, with about 130 kDa being the best, according to the most recent human studies. Anything higher won’t make too much of a difference. Anything lower might cause inflammation.

How did we get this number? When you look at studies, you’ll see a pattern, but one of the most thorough studies looked at HA with different molecular weights, including 50, 130, 300, 800, and 2,000 kDa.

After one month, they found that treatment with 130 kDa HA was the most effective, increasing skin elasticity by 20 percent. Both the 50 and 130 kDa groups had significant improvement in wrinkle-depth and skin roughness after 60 days. All the other molecular weights still improved elasticity and skin hydration, just less so.
Diameter of hyaluronic acid
The diameter of hyaluronic acid is also important as it too determines the ingredient’s ability to penetrate the skin. A recent study investigated the efficacy of a topical, low molecular nano-hyaluroid acid, and found that smaller substances under 500 kDa:

  • changed the depth of wrinkles
  • increased moisture
  • increased elasticity around the eye
  • absorbed into the skin better

Larger molecules, with a molecular weight greater than 500 kDa, had a more difficult time passing through the skin barrier.

What products should you use?

There are skin care products out there that take away all the guesswork for you by combining various HA molecules for maximum effectiveness. It’s like a jam-packed party of hyaluronic acid-y goodness.

HA ingredients to look for

  • hydrolyzed hyaluronic acid
  • sodium acetylated hyaluronate
  • sodium hyaluronate

One such example is the Hada Labo Hyaluronic Acid Lotion ($13.99), from a Japanese cosmetic company. It comes with three different types of HA, including hydrolyzed hyaluronic acid, sodium acetylated hyaluronate, and sodium hyaluronate. It works great, and is something to use after dermarolling to speed up the healing process.


What It Is
Retinol is a powerful ingredient derived from vitamin A that stimulates collagen production and encourages cell turnover. “In this family, we have retinol, retinaldehyde, and retinoic acids,” explains Linder. “Retinol has to be converted to retinaldehyde then to retinoic acid in the tissue. Retinoic acid is the only retinoid that works to stimulate collagen so conversion is absolutely necessary for the product to work. You can get retinoic acid in a prescription form (Retin-A) and retinols are available over the counter or in medical offices.”

Retinol products are widely prescribed by many skincare specialists, dermatologists, and aesthetic practitioners. “Retinol serums can work on the skin in a few different ways, like stimulating collagen production. It will help to prevent wrinkles from forming while filling out any existing fine lines or wrinkles,” says Hu. “Retinol serums will also exfoliate dead skin cells to reveal a brighter, smoother skin underneath. They also help to fade dark spots, sun spots, and hyperpigmentation.”
How It Works With Hyaluronic Acid
The experts say that retinol and hyaluronic acid work well together, as they balance one another out.

“Retinol and hyaluronic acid are a perfect pair,” says Linder. “Hyaluronic acid acts as a buffering mechanism against some of the irritation that the skin can experience with retinoids. You can reap the benefits of retinol without any of the irritating side effects due to the moisturizing boost from hyaluronic acid.”


What It Is
Niacinamide is a vitamin B derivative that is water-soluble. “Also known as vitamin B3, niacinamide is naturally occurring and essential to healthy skin cell functions,” says Hu. “Niacinamide… can effectively clear acne, minimize pores, fade discoloration, and even reduce fine lines and wrinkles. The ingredient is also highly compatible with almost any product in your current skincare routine so you can easily introduce it without the concern of facing a breakout or causing irritation.”

How It Works With Hyaluronic Acid
The experts say niacinamide and hyaluronic acid pair well together, and you may just find both as ingredients in your favorite moisturizing products. “Niacinamide and hyaluronic acid are both water-based ingredients that work well together for overall hydrating results, leaving the skin rejuvenated and minimizing the sign of aging and fine lines,” says Hu.

Vitamin C

What It Is
Vitamin C is a powerful antioxidant and essential nutrient that humans do not produce on their own. Vitamin C protects your skin cells from damaging free radicals and encourages skin cell turnover, meaning it generally keeps skin cells healthy and prevents damage from UV exposure. That being said, Sperling notes, “it is always important to match your vitamin c products with a good sunscreen.”

“Vitamin C is most known for a variety of benefits such as anti-inflammatory effects, stimulating new collagen growth (neocollagenesis), providing powerful antioxidant protection, and inhibiting melanogenesis (darker pigmentation),” says Liner. “Clinical studies have shown vitamin C helps with fine lines and coarse wrinkles, skin texture and tone, and yellowing and discoloration, and improves hydration, elasticity, and skin firmness.”
How It Works With Hyaluronic Acid

Vitamin C and hyaluronic acid as a combo can typically have results similar to low-dose retinol. “Vitamin C and hyaluronic acid work together by brightening and hydrating the skin,” Hu says. “Together these two ingredients can visibly dissolve wrinkles and improve the skin’s texture and appearance. ”

Salicylic Acid

What It Is
Salicylic Acid is a beta-hydroxy acid that occurs as a natural compound in plants. BHAs are more oil-soluble, which means they can easily break through the skin cells’ lipid layers and penetrate the skin at a deeper level than water-soluble products and are anti-inflammatory agents. Salicylic Acid acts as a topical antibacterial agent due to its ability to promote exfoliation.

“Salicylic acid is most typically found in acne face washes and cleansers or spot treatments,” says Hu. “It can deeply penetrate the skin and go beyond just the surface layer; it’s a really powerful acne-fighting ingredient.” Sperling Adds: “helps removes excess oils from the skin. It also helps treat whiteheads and blackheads while decreasing pore size.”

How It Works With Hyaluronic Acid
Hyaluronic acid generally compliments salicylic acid with its hydrating benefits. “Salicylic acid can sometimes make the skin feel dry after use,” Hu says. “When paired with hyaluronic acid, the skin can have access to more moisture and seal that moisture in.”

Glycolic Acid

What It Is

Glycolic Acid is an AHA (alpha-hydroxy acid) derived from sugarcane that has anti-inflammatory effects.”water-soluble alpha-hydroxy acid,” Hu shares. “This natural acid consists of tiny molecules making it easier for your skin to absorb. With its ability to quickly absorb into the skin glycolic acid acts as an exfoliant, making it ideal for smoothing fine lines, improving skin texture, and triggering your skin to make more collagen. Glycolic acid is also used to help with any sun damage or acne scars by cleaning out the pores.”

How It Works With Hyaluronic Acid
Glycolic acid generally works as an exfoliator and hyaluronic acid as a hydrator, so experts say the two pair well together. “Glycolic acid increases cell turnover, which can sometimes lead to skin irritation, so it is important to pair it with a moisturizing element, such as hyaluronic acid,” says Hu. “Using the two together can lead to brighter, dewier skin.”

Lactic Acid

What It Is
Lactic Acid is an exfoliant that technically derives from… spoiled milk. Yes, you read that correctly. “Derived from the fermentation of lactose, which is a carbohydrate found in milk, lactic acid is a chemical exfoliant, more specifically an alpha hydroxy acid (AHA), that works to hydrate skin and improve the overall appearance,” Hu says. “Lactic acid is known to increase cell turnover, which helps eliminate dead skin, leading to a brighter and smoother complexion. It is a mild form of AHA, making this a great option for those with sensitive skin.”

How It Works With Hyaluronic Acid
Similar to glycolic acid, this exfoliant pairs nicely with hyaluronic acid. “While lactic acid is exfoliating, hyaluronic acid is hydrating,” Hu says. “Lactic acid shaves away any dead skin cells that have built up, which can lead to flaky skin and breakouts. However, when combined with the nourishing and moisturizing properties of hyaluronic acid, the two acids can lead to soft, smooth, and hydrated skin, helping you achieve a clear and glowing complexion.”

What is hyaluronic acid best paired with?

Vitamin C. Yes, these two superstars can give your skin a super anti-ageing boost with Hyaluronic Acid’s plumping and hydrating qualities along with Vitamin C’s antioxidant and brightening properties. … Ceramides. … Retinol. … Panthenol. … AHAs & BHAs.