And as far as faux holidays go, this one is pretty easy to celebrate: Simply apply your favorite pillowy hyaluronic acid serum for instantly plumper skin. But that’s not the only way you can take advantage of the beloved hydrator! Below, find some underrated (yet powerful) ways to observe the HA holiday. Your supple, Jello skin will surely thank you later. And in case you need a friendly reminder: Your lip skin is, well, skin. Humectants like HA help pull moisture from the air into the upper layer of that skin to keep the cells hydrated and plump, without any of the stinging or burning that often comes with traditional lip plumpers. Hyaluronic acid works so well, in fact, that it has become the workhorse ingredient for many hi-tech topical lip fillers, including the Ourself Lip Filler. Specifically, this formula features multi-weight hyaluronic acid and vitamin B3 derivatives to smooth the look of lip lines and provide instant volume. (I’ve personally tested it, and trust me: It works.) If you choose to use a balm, just make sure it also has emollients and occlusives (like butters and oils) to keep all that water locked inside—here are our favorite options that provide just the right amount of volume. To restore those levels, many experts recommend opting for a hyaluronic acid supplement. Think about it: If you regularly apply a HA serum for dewy skin, why wouldn’t you want to double down for even more skin-quenching benefits? (That’s why you can find it in Hailey Bieber’s skin-loving Erewhon smoothie, famously tagged at $17.) Here’s a list of our favorite supplements, all vetted by a nutrition Ph.D. Plenty of leave-ins, shampoos, and stylers include the ingredient in their formulas already—but you can apply a proper HA serum to your locks for a targeted treatment. “HA lives in my shower for the face and hair,” says board-certified internal medicine physician and skin care expert Zion Ko Lamm, M.D., on Instagram. Feel free to massage it into the scalp as well; like the skin on your face, your scalp can always use some extra T.L.C. Again, just make sure you seal in all that hydration with a moisturizing oil. You’ll also want to apply the HA on damp hair, so that the humectant has enough water to attract.