Polyglutamic Acid vs. Hyaluronic Acid: What's the Difference, and Do You Need Both?

Hyaluronic acid has ruled hydrating skincare for years, but a newer ingredient is quietly proving it deserves a spot on your shelf too. Here's all you need to know about polyglutamic acid.

You’ve probably heard of hyaluronic acid, an ingredient that’s been prominent in the skincare field for years. More recently, a new player is gaining attention: polyglutamic acid, or PGA, and if you’re wondering what it is and how this affects your current skincare routine, here’s what you should know.

PGA is a humectant. That means it attracts and holds water at the skin's surface. Produced by fermenting glutamic acid, a form of amino acid naturally found in the body, PGA was first discovered in natto, a fermented soybean dish.

On why this is drawing attention, according to board-certified dermatologist Divya Shokeen, MD, "It is a powerful humectant capable of holding up to four to five times more moisture than hyaluronic acid."

Beyond simply adding moisture, PGA may also help boost the skin's own hydration abilities. According to Cara Bondi, VP of product at Sol de Janeiro, PGA works by increasing the skin's "natural moisturizing factor," a complex of molecules that helps the skin retain and manage moisture on its own.

Compared to hyaluronic acid, PGA is a larger molecule, so it tends to remain on the skin's surface, forming a protective, hydrating film.

On the other hand, hyaluronic acid comes in various molecular weights, allowing for deeper penetration and hydration, reaching multiple layers of skin.

The good news is you don't have to choose one over the other. "Since many people already have HA in their routine, PGA can be another way to add an extra layer of hydration," says dermatologist Rishi Chopra, MD.

"If your skin barrier needs surface-level moisture retention, smoothing, or a dewier finish, PGA is fantastic," Dr. Shokeen explains. "Using both together gives the ultimate hydration experience." Both ingredients may also be used together with retinol and vitamin C.

PGA isn’t limited to any skin type. It’s strong enough for dry, dehydrated, and mature skin, but also gentle enough for sensitive and acne-prone skin. However, a word of caution for those with very oily skin or in humid climates: its protective film may feel heavy or sticky.

The bottom line is PGA isn't a replacement for hyaluronic acid. It's another item to add to your hydration routine.