The Ordinary Hyaluronic Acid Guide: How to Use It

Hyaluronic acid is one of the most widely used ingredients in skincare — and The Ordinary's Hyaluronic Acid 2% + B5 serum is one of the most popular products in their entire range. It's inexpensive, well-formulated, and suitable for all skin types. But there are two versions, and using any HA serum incorrectly can actually work against you.

This guide covers what hyaluronic acid is, how The Ordinary's two serums differ, how to apply them correctly (including the one step most people skip), and how the Skincare Routine app fits it all together automatically.

What is hyaluronic acid?

Hyaluronic acid (HA) is a molecule naturally found in the skin with exceptional water-binding properties. It acts as a humectant — it draws water molecules to itself and holds them, hydrating and plumping the skin. A single HA molecule can hold up to 1,000 times its own weight in water.

The Ordinary describes it as "a molecule with water-binding properties that hydrates and plumps skin."

The catch is that HA molecules come in different sizes, and size determines where they can act in the skin. High-molecular-weight HA is too large to penetrate the skin's surface and works by holding moisture at the top layer. Low-molecular-weight HA can penetrate more deeply and hydrate at multiple levels. Skin care formulators use a mix of both to achieve multi-depth hydration — which is exactly what The Ordinary has done in both of their HA serums.

What is pro-vitamin B5?

Both The Ordinary HA serums contain panthenol, the provitamin form of B5. Panthenol supports the formation of ceramides and fatty acids in the skin — the key components of a healthy moisture barrier. It also enhances the skin's ability to retain moisture. In short, B5 helps lock in the hydration that the hyaluronic acid draws in.

The two products: which one is right for you?

The Ordinary currently offers two versions of their Hyaluronic Acid 2% + B5 serum. They share the same core function but differ in formulation and texture.

Hyaluronic Acid 2% + B5 (Original Formulation)

The original serum contains 4 types of hyaluronic acid: low-, medium-, and high-molecular-weight hyaluronic acid molecules, plus a next-generation HA crosspolymer. These work together to hydrate the skin at multiple depths, supporting a smooth, healthy appearance.

It also contains pro-vitamin B5 (panthenol) to further support barrier function and moisture retention.

The original formulation has a richer texture compared to the newer version.

Targets: Dehydration, Dryness
Suited to: All skin types
Format: Water-based serum
pH: 6.0–7.5

Clinical testing (34 subjects, 2x/day for 4 weeks) showed:

Replenished skin hydration
Strengthened the skin barrier
After 4 weeks: enhanced skin smoothness, boosted elasticity and firmness

Hyaluronic Acid 2% + B5 (with Ceramides)

The newer, second-generation formulation builds on the original. It contains 5 types of hyaluronic acid: the original four, plus hydrolyzed hyaluronic acid — an additional ultra-small fragment that penetrates even further into the skin's layers.

The key addition is ceramides — natural lipids found in the skin that lock water in while strengthening the moisture barrier. Ceramides are a fundamental building block of healthy skin; this formulation includes both phospholipids and sphingolipids to supplement the skin's own ceramide reserves.

The ceramides version has a lighter, non-tacky texture that absorbs quickly, making it easy to layer with other products.

Targets: Dehydration, Signs of Aging
Suited to: All skin types
Format: Water-based serum
pH: 6.0–7.5

Clinical testing (32 people, 2x/day) showed:

Instantly: Skin is hydrated, barrier is supported
After 1 week: Skin feels smoother and softer; hydration levels increase week over week
After 2 weeks: Skin is firmer and more plump
After 4 weeks: Lines and wrinkles look smoothed, nasolabial folds look plumper, elasticity and suppleness are improved

Which should you choose?

	Original Formulation	With Ceramides
Types of HA	4	5
Ceramides	No	Yes
Texture	Richer	Lightweight, non-tacky
Targets	Dehydration, Dryness	Dehydration, Signs of Aging
Best for	Those who prefer a richer feel	Those who prefer a lighter serum or want barrier support + anti-aging benefits

If you're choosing for the first time, the ceramides version is the more comprehensive formula: it delivers all the hydration of the original, adds ceramides for enhanced barrier support, and comes in a lighter texture that layers well with anything.

If you prefer a richer, more emollient feel — particularly useful for very dry or sensitive skin that does well with a heavier serum — the original formulation is the one for you.

The most important rule: apply to damp skin

This is the step most people miss, and it matters more with HA than with almost any other serum.

Hyaluronic acid draws moisture from its environment. On damp skin, it draws moisture up from the deeper layers of the dermis and holds it at the surface. In a dry environment, however — or when applied to dry skin — it can pull moisture upward and allow it to evaporate off the surface, potentially leaving skin feeling drier than before.

Always apply The Ordinary Hyaluronic Acid to slightly damp skin, then immediately follow with a moisturiser to seal the hydration in. Pat your skin dry (not completely) after cleansing and apply the serum while your face is still slightly moist.

This applies to both versions.

Where does it fit in your routine?

Both HA serums are water-based and lightweight, which means they go on early in your routine — after cleansing and toning, before heavier serums, oils, and moisturisers.

The layering principle is: lightest to heaviest. HA serums are among the lightest products in any routine.

Example AM routine

Cleanser
Hyaluronic Acid 2% + B5 (applied to damp skin)
Niacinamide 10% + Zinc 1% (or other water-based serum)
Moisturiser
SPF

Example PM routine

Cleanser
Hyaluronic Acid 2% + B5 (applied to damp skin)
Treatment serum (e.g. retinoid or peptide serum)
Oil (e.g. Squalane)
Moisturiser

Key rule: Always follow HA with a moisturiser in the same step, not later. If you apply HA and then wait even a few minutes before moisturising — especially in a dry or air-conditioned room — that humectant draw can work against you.

What to pair it with

The Ordinary's HA serums are exceptionally compatible — there are no known conflicts with other The Ordinary products. Think of them as a foundation for hydration that almost anything else can sit on top of.

Great pairings:

Natural Moisturizing Factors + HA — The obvious companion. Apply the HA serum first, then seal it with NMF + HA moisturiser. This is The Ordinary's own recommended everyday regimen.
Niacinamide 10% + Zinc 1% — Apply the HA serum first (the lighter product), then Niacinamide. These two work well together.
"Buffet" multi-peptide serum — Apply HA first, then Buffet. Peptides and HA complement each other well.
Retinoids (Granactive Retinoid, Retinol in Squalane) — In a PM routine, HA goes on before the retinoid. It helps hydrate the skin before a potentially drying active.
Squalane — Apply HA first (water-based), then Squalane (oil-based) to seal it in.
Any AHA or BHA exfoliant — HA pairs well with exfoliating acids by helping replenish moisture and support the barrier afterwards. Apply HA after your acid has fully absorbed.

There are no conflicts with the HA serums in The Ordinary's range. They sit in routines with virtually all other products.

How the Skincare Routine app makes this effortless

Knowing hyaluronic acid should go on damp skin, before your moisturiser, after your toner — it's a lot to keep in your head while also remembering whether last night was a retinol night or an acid night.

The Skincare Routine app handles all of this automatically.

Both HA serums are pre-loaded

Both Hyaluronic Acid 2% + B5 (Original Formulation) and Hyaluronic Acid 2% + B5 (with Ceramides) are pre-loaded in the app, complete with the correct layer step, AM/PM availability, and compatibility rules.

Your routine is sorted into the right order automatically

When you add both an HA serum and a Niacinamide serum to your routine, the app automatically places the HA serum first — because it's lighter. If you add a retinoid, the app places the HA serum before it. The ordering is based on DECIEM's own recommendations and the lightest-to-heaviest rule. You can always reorder manually if you prefer.

No conflicts to worry about

The HA serums have no conflicts in The Ordinary's range, and the app will confirm this. When you tick off products during your routine, incompatible combinations show up as red or orange checkboxes — with the HA serums, you'll never see a conflict flag, no matter what else you have in your routine.

Track your skin's response

After you add hyaluronic acid and notice your skin looking plumper and more hydrated after a couple of weeks, you can log it. Every time you complete your AM or PM routine in the app, you can rate how your skin looks and feels. Over time this builds a picture of which products are genuinely making a difference for your skin.

Available on iOS and Android

Download at skincareroutine.app or search "Skincare Routine" on the App Store or Google Play.

Summary

	Original Formulation	With Ceramides
HA types	4	5
Ceramides	—	✓
Texture	Rich	Lightweight
Anti-aging claims	No	Yes
When to use	AM + PM	AM + PM
Layer step	After toner, before heavier serums	After toner, before heavier serums

Hyaluronic acid is one of the simplest, most universally beneficial skincare ingredients — but like any active, it rewards correct use. Apply it to damp skin, seal it with a moisturiser immediately after, and let it do its job. The Ordinary's formulations are among the best-value HA serums available, and the Skincare Routine app will make sure you're always using them at the right step, in the right order, alongside everything else in your routine.