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Written by OSEA Staff | Published June 8, 2026
Hyaluronic acid is one of skincare's most buzzed-about ingredients. We often associate it with hydrated, visibly firmer skin, but what exactly is the molecule known as HA, and what does it do? And if it truly is one of the best anti-aging ingredients out there, what's the right way to incorporate it into your daily routine? Ahead, your ultimate guide to hyaluronic acid.
What Is Hyaluronic Acid?
First things first. Despite the “acid” in the name, hyaluronic acid is not exfoliating and isn’t your typical acid. It’s a polysaccharide. In laymen’s terms, it’s a sugar molecule that naturally occurs in our connective tissue, joints, hair, skin and eyes. Known for being hydrophilic, meaning it draws and holds onto water, it plays an essential role in retaining moisture in our tissues.
HA can be found in both topical skincare and injectable filler forms. In topical formulas, it can be used in low, medium, or high molecular weights, each with its own benefits. The bottom line: A combination formula helps maximize moisture on every level.
Benefits of Hyaluronic Acid
As a powerful humectant (a substance which attracts water), hyaluronic acid not only brings moisture in, but it helps skin hold onto it too. It pulls moisture in from the air to help maintain water levels in your skin. As we age, our natural levels of hyaluronic acid decline, which is one reason skin can begin to look less firm, plump and smooth over time. Adding topical hyaluronic acid to your skincare routine is a simple way to help restore hydration and maintain a youthful-looking glow.
Its superpower is holding onto hydration; and because it’s ideal for all skin types, it’s something we love to use in our products, especially when combined with our nutrient-rich seaweed. Practically weightless, it sinks into skin instantly, hydrating, visibly firming and smoothing skin.
Hyaluronic Acid vs Sodium Hyaluronate
Here’s a little chemistry lesson: hyaluronic acid has a sister counterpart called sodium hyaluronate. Sodium hyaluronate is a salt derivative of hyaluronic acid with similar hydrating benefits. It’s often used in skincare because of its smaller molecular size. We use both hyaluronic acid and sodium hyaluronate in our seaweed-powered formulations.
How to Use It
Hyaluronic acid is found in a wide range of skincare products, including serums, moisturizers, mists and masks. This clever molecule can be a powerful step in your routine, but it works best when layered properly. Because hyaluronic acid attracts water, it should be followed with a moisturizer, cream or facial oil to help seal in hydration and keep skin looking bouncy, smooth and dewy.
The Best Hyaluronic Serums
Ready to get started with hyaluronic acid? We’ve got just the thing. One of the simplest and most effective ways to start incorporating this powerful ingredient into your routine is with HA serums. Twice a day, after cleansing, apply a few drops of our Hyaluronic Sea Serum to your face and neck. Our bestselling serum uses two different types of hyaluronic acid—one high molecular weight, one low—to synergistically boost hydration, fullness and firmness of the skin. There’s also Japanese Miru seaweed to replenish and balance the skin’s natural hydration levels, as well as snow mushroom (Tremella fuciformis), which acts as both a humectant and an emollient, drawing water to the skin, then sealing it in for a more bouncy, plump look. The clinical results speak for themselves. In a third-party study, 100% of participants showed an improvement in fine lines and wrinkles.* Our skin just drinks it up, and we can really see the difference in how hydrated and smooth it looks and feels afterward.
*Based on an independent third-party clinical study
For the other 91% of your skin — aka your body — there’s our Hyaluronic Body Serum. This ultra-hydrating full body treatment is clinically shown to instantly increase hydration by 161%.* It delivers all of the hydrating properties of our hyaluronic facial serum but is formulated specifically for the skin on your body. This lightweight, fast-absorbing serum improves the skin’s natural moisture barrier for visibly healthy, smooth skin everywhere. Packed with five molecular weights of hyaluronic acid, aloe, vegan peptides and nutrient-dense seaweed, this full-body treatment delivers 24 hours of non-stop hydration. The larger hyaluronic acid molecules create a water reservoir at the skin’s surface to attract moisture. The in-between-sized molecules help improve suppleness, while the mini-sized molecules instantly penetrate and absorb easily for a boost of hydration.
*Based on an independent third-party clinical study
More Hyaluronic Acid Heroes
Beyond face and body serums, hyaluronic acid can be found in multitasking formulas that bring its hydrating benefits to everyday essentials. From SPF to lip care, these seaweed-powered formulas make it easy to incorporate HA into your daily routine.
Hydrating Sun Protection
Meet Marine Screen SPF 50, a daily mineral sunscreen designed for the sun you live in. This clean, lightweight, fragrance-free formula delivers broad-spectrum SPF 50 protection to help prevent visible signs of aging while nourishing skin. Our unique formula goes beyond traditional sun protection by combining non-nano zinc oxide protection with marine-enriched skincare benefits. Sustainably sourced in Brittany, France and packed with amino acids and antioxidants, our signature ingredient, Undaria seaweed, helps mineralize skin. Hyaluronic acid boosts hydration for a softer, smoother complexion, while an olive-derived natural silicone alternative gives the formula its unique lightweight, non-greasy texture, helping it glide on and blend in effortlessly. The result is a mineral sunscreen that feels less like SPF and more like skincare. Because it is.
Hyaluronic Acid Lip Plumpers
For your daily plumping hydration step, reach for our Hyaluronic Lip Oil Booster. This juicy, non-sticky lip oil delivers the high-shine of a gloss with the nourishment of a balm, for a softer, plumper-looking pout. A combination of hyaluronic acid and sea fern helps promote visibly plumper, fuller-looking lips, while castor oil and meadowfoam oil nourish and condition. Rich yet lusciously lightweight in texture, our lip oil features a deliciously sweet mango-mandarin scent. The clear, glossy sheen is gorgeous alone and layers beautifully over lipstick or tints. Swipe it on day or night, or whenever your lips need a boost of instant hydration and shine.
