This Hyaluronic Acid Serum Is So Good, I Used It Down To The Last Drop

As a beauty editor, part of my job is testing products—a lot of products. It's definitely a perk of the job, but it also means I'm constantly introducing new formulas to my routine so I can relay the best, most informed recommendations. That said, it usually takes me a while before I finish an entire jar of product. So when I absolutely fly through a sample and can't wait to get my hands on another bottle, you can trust that it's good. Really good. 

Hyaluronic acid is a humectant, which means it pulls in water to hydrate your skin and provides an immediate plumping effect. But this Oasis serum raises the bar: It contains four (yes, four) different types of hyaluronic acid, including sodium hyaluronate, hydrolyzed sodium hyaluronate, sodium hyaluronate crosspolymer, and sodium acetylated hyaluronate. 

If those science-y words give you pause, don't sweat: All "hydrolyzed" means is breaking the chemical down with water so it's easier for your skin to absorb. Sodium hyaluronate, a salt form of hyaluronic acid, has an even smaller molecular weight than hydrolyzed HA, so it really works its way into the deep layers of your skin. Because this serum features a blend of four molecular weights of hyaluronic acid, it can truly plump each layer of your skin. 

The formula also features three types of peptides to help the skin appear more firm and youthful. Specifically, it contains palmitoyl tetrapeptide-7, which is thought to help maintain a healthy inflammatory response and stimulate skin regeneration, especially for those with sensitive skin1. You can read all about the different kinds of peptides here, but in general, they are worthy additions to any healthy aging routine. "When you apply [peptides] topically like in a serum or moisturizer you are telling your skin to create more collagen," New York City–based esthetician Taylor Worden previously shared with mbg.

I'm such a fan of this serum (and my impossibly dewy skin) that I used it both morning and night. In the morning, I layer it on top of a vitamin C number, then follow up with moisturizer and sunscreen. At night, I either sandwich it between my actives (an AHA toner or retinol serum, depending on the day) or use it on its own before slathering on a night cream. It seamlessly fits into my routine, no matter the day, to supply my skin with an extra splash of hydration.