You’ve been seeing it everywhere: hyaluronic acid is found in almost every moisturizing product on the shelf these days. Not sure what it is? You’re not alone.

Hyaluronic acid is one of those ingredients people have heard about (probably from Olivia Munn) but hardly know the reason behind the hype. Well, get ready to impress your friends with all the fast facts we’re about to lay on you.

Also known as sodium hyaluronate, hyaluronic acid (or HA for short) is a polysaccharide (sugar!) that naturally occurs in our body’s tissues. Its claim to fame? Hydration, stability and lubrication, aka it makes your skin feel and appear dewy, plump and healthy.

Okay, but if hyaluronic acid occurs naturally in our bodies, then why do we need to apply it topically?

Great question, you little overachiever! According to the Journal of Dermato Endocrinology, “[Hyaluronic acid] is the key molecule involved in skin moisture and has a unique capacity to retain water. This is important because skin aging is associated with the loss of skin moisture.” Translation: When we age, the amount of hyaluronic acid our skin cells produce begins to decrease. Not to mention, cell turnover can become slowed, which accelerates the appearance of fine lines, wrinkles and a dull complexion (I know, we’re cringing, too).

In other words, we need to apply HA topically to supplement the amount we lose naturally as we age.

What else should I know about HA?

Um, that it’s amazing for all skin types, for one. In fact, it’s pretty much a must-have ingredient if your skin is prone to dehydration—it holds up to 1,000 times its weight in water! And in case you haven’t had enough health nuts lecturing you about the importance of water, consider this your friendly reminder.

Oh! And another thing... don’t confuse hyaluronic acid with exfoliating acids. Quick refresher: exfoliating acids help clear blemishes, hydrate your skin and lighten pigment spots by loosening layers of dead cells clinging to the skin’s surface. Hyaluronic acid is a powerful, moisture-blinding, gentle gel that hydrates and softens when used regularly.

Got it. Do you have any topical products you’d recommend?

Of course we do! At the end of the day, hyaluronic acid is best used in its purest form as a serum, with limited additional ingredients. The bottom line? You’ll get way better results this way. Also, be sure to look for products that contain SLMW (super low molecular weight) hyaluronic acid—it penetrates deeper and allows the use of a higher percentage—or MMW (multi molecular weight) hyaluronic acid, which penetrates at different levels, allowing for instantly hydrated, plump, baby-soft skin.

Here are some of the best hyaluronic acid serums:

• Otto Skin Goods Go-Getter Day Serum (5% super low molecular weight hyaluronic acid) $74
• Glossier Super Bounce (2% hyaluronic complex) $28
• Pestle & Mortar Pure Hyaluronic Serum (multi-molecular weight hyaluronic acid) $59
• Dr. Barbara Sturm Hyaluronic Serum (long- and short-chain hyaluronic acid) $300

Phew! We covered a lot today. Bet you feel a lot smarter, don’t you? There’s a lot to unpack about hyaluronic acid, so be sure to leave a comment below with any burning questions!