Hyaluronic acid isn't an acid. Here's what it actually does.

You've seen "hyaluronic acid" on a hundred labels. Here is what it is.

It isn't an acid. It's a humectant: a molecule that pulls water toward itself and holds it. Your body makes it, about half of it in your skin, and makes less as the years go by. That is one reason skin that used to look plump starts to look dry.

In a cream, HA does one job well: it draws moisture toward the surface layers where dryness shows first. It does not, on its own, keep it there. That takes a second ingredient, and most creams that put hyaluronic acid on the front of the jar stop there. The water arrives, the skin looks plump for a while, and by the afternoon it has gone the way water goes.

That isn't a flaw in hyaluronic acid. It's what the molecule is for. HA is a sugar your skin already makes, famous for holding many times its own weight in water, and in a cream its job is the plump, rested look that hydration gives. It's a strong teammate. It was never going to be the whole team.

Keeping moisture where HA puts it is a separate job, and it takes separate ingredients. In our Deep Moisturizer, HA works alongside two water-management peptides of natural origin: one chosen to help move moisture toward the surface layers where dryness shows first, one to bind it there. Both meet the Ecocert standard for natural-origin cosmetics. Then there's squalane, a lipid your skin makes less of with every decade; replenished, it reads as softness, and it's the reason the formula feels cushiony instead of watery. Chamomile and aloe, both certified organic, keep a deeply hydrating cream gentle enough for the face, neck and hands. A vitamin layer of E, C, B3, B5 and B6 finishes it.

So when you see hyaluronic acid on the front of a jar, the question to ask is what's behind it. Turn it over. If HA (it may be listed as sodium hyaluronate) is there with a lot of water, an emulsifier and a fragrance, the cream will feel lovely for an hour. If it's there with something that binds moisture and something that replaces the lipids skin loses, it's a hydration formula.

Two notes on using it, since people ask. HA works best applied to skin that's slightly damp, because it needs water to pull toward the surface. And if you use a separate HA serum, follow it with a cream that seals; on its own in dry air it can leave skin feeling tighter than before, which is the molecule doing exactly what it does with nothing to hold onto.

Every ingredient in Deep Moisturizer is named on the jar and on our science page. Google any of them.

-Jackie