What is hyaluronic acid?

It turns out, we have it in our own body—hyaluronic acid is naturally found in our skin, eyes, and connective tissue. It’s the stuff that keeps skin plump and hydrated. In skincare and hair products, hyaluronic acid is a gel-like molecule, typically derived from sugars. It acts as a humectant, grabbing onto an impressive amount of water—up to 1000 times its weight. That’s also why hyaluronic acid is also used in injectable fillers. It can pump up thin lips, volumize hollow cheeks, and literally fill in wrinkles and creases for several months at a time.

So, how does it help your hair?

Hair care brands have only recently started to harness hyaluronic acid’s insane moisture-binding abilities. When applied topically to damp hair, hyaluronic acid acts like a sponge. It soaks up outside moisture and holds it in, making hair strands more hydrated, elastic, and overall healthier. It’s an especially good ingredient for hair that’s extremely dry and damaged. This hair type tends to be more porous (think full of holes like Swiss cheese) and has an especially hard time holding onto its moisture. Hyaluronic acid fills in these holes so hair can receive— and hang on to—water. Why is that important? For one, hydrated hair just looks healthier, but it’s also more resilient. It’s able to better withstand everyday stress inflicted by combing, brushing and heat styling.

While hyaluronic acid is a strand superstar, researchers have found that it works even better when it gets a little help from its friend collagen, a protein found in our bodies that’s also essential for healthy skin and hair. Together they work synergistically to repair hair’s core while nourishing hair’s outer layer. Prose products combine hyaluronic acid with a vegan form of collagen (derived from the acacia tree), along with lilac for intense hydration and repair.