Ingredient review

Sodium Hyaluronate Crosspolymer-4

INCI: SODIUM HYALURONATE CROSSPOLYMER-4

A next-gen hyaluronic acid that clings to skin longer for deep, lasting hydration without the sticky feel.

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In plain English

Sodium Hyaluronate Crosspolymer-4 is a souped-up version of hyaluronic acid, a natural moisture magnet in your skin. Think of regular hyaluronic acid as a sponge that soaks up water but dries out quickly. This crosspolymer version is like a network of tiny sponges linked together, so it holds onto moisture for much longer and stays put on your skin's surface, giving you a smoother, plumper look without feeling tacky.

Review score

Safety, usefulness, and evidence

4.5Excellent
4.5/ 5

Strong fit for many routines

The evidence base is useful, but some claims depend heavily on the formula.

Risk flags are low for most users, though the finished product can still irritate.

Source
semi synthetic
Evidence
moderate
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Easy yes for most routines

Sodium Hyaluronate Crosspolymer-4 is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Sodium Hyaluronate Crosspolymer-4.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

It is a chemically modified form of sodium hyaluronate (the salt form of hyaluronic acid) where individual molecules are crosslinked into a larger, more stable polymer network. This structure resists rapid breakdown and stays on the skin's surface longer.

How it works

It forms a flexible, invisible film on the skin that attracts and holds water from the environment and deeper skin layers. Because the molecules are crosslinked, they don't penetrate deeply but instead create a reservoir of moisture on the skin's surface, reducing water loss (transepidermal water loss, or TEWL) and providing a plumping, smoothing effect.

Pros

Lasting Hydration

The crosslinked structure holds water on the skin for hours longer than regular hyaluronic acid, so you don't need to reapply as often.

Lightweight Feel

Despite its powerful moisture-binding ability, it feels light and non-greasy on the skin, making it suitable for layering under makeup or sunscreen.

Cons and cautions

Potential Stickiness

In high concentrations or if applied too thickly, it can leave a slightly tacky residue that may feel uncomfortable for some users.

Limited Research

Compared to standard hyaluronic acid, there are fewer independent studies on this specific crosspolymer, though existing safety data is reassuring.

Best for

  • Anyone with dry or dehydrated skin looking for lasting moisture
  • People who want a plumping effect without invasive treatments
  • Those with sensitive skin who tolerate standard hyaluronic acid well

Use caution if

  • Individuals with known allergies to hyaluronic acid or its derivatives (rare)

Usage tips

Apply to damp skin to maximize water-binding and reduce any tackiness.
Layer it under a moisturizer with occlusive ingredients (like shea butter or squalane) to lock in the hydration.
Use it in your morning routine for a smooth base under makeup.

Safety summary

Sodium Hyaluronate Crosspolymer-4 is considered safe for topical use. It is non-irritating and non-comedogenic for most skin types. Rare allergic reactions are possible but very uncommon. Always patch test a new product.

Research notes

Research on crosspolymer hyaluronic acids shows they provide superior surface hydration and barrier support compared to linear hyaluronic acid. Most studies are sponsored by ingredient manufacturers, but independent dermatological reviews support its safety and efficacy for cosmetic use.

Common label clues

Typical concentration
0.1% to 1%
Regulatory status
Approved for use in cosmetics in the US, EU, and other major markets. No specific restrictions beyond general cosmetic safety requirements.
Common uses
Serums, Moisturizers, Eye creams, Sheet masks
Environmental note
Produced via biotechnological fermentation, which is generally more sustainable than animal-derived hyaluronic acid. No known significant environmental concerns.

Good to know

  • This ingredient is often listed near the end of ingredient lists because it is effective at low concentrations.
  • It is compatible with most other skincare ingredients, including vitamin C and retinol.

Common questions

What is Sodium Hyaluronate Crosspolymer-4 in beauty products?

Sodium Hyaluronate Crosspolymer-4 is a souped-up version of hyaluronic acid, a natural moisture magnet in your skin. Think of regular hyaluronic acid as a sponge that soaks up water but dries out quickly. This crosspolymer version is like a network of tiny sponges linked together, so it holds onto moisture for much longer and stays put on your skin's surface, giving you a smoother, plumper look without feeling tacky.

What does Sodium Hyaluronate Crosspolymer-4 do in a beauty product?

It forms a flexible, invisible film on the skin that attracts and holds water from the environment and deeper skin layers. Because the molecules are crosslinked, they don't penetrate deeply but instead create a reservoir of moisture on the skin's surface, reducing water loss (transepidermal water loss, or TEWL) and providing a plumping, smoothing effect.

Is Sodium Hyaluronate Crosspolymer-4 safe for most people?

Sodium Hyaluronate Crosspolymer-4 is considered safe for topical use. It is non-irritating and non-comedogenic for most skin types. Rare allergic reactions are possible but very uncommon. Always patch test a new product.

Who should be careful with Sodium Hyaluronate Crosspolymer-4?

Individuals with known allergies to hyaluronic acid or its derivatives (rare)

Research sources

Cosmetic Ingredient Review (CIR) - Safety Assessment of Hyaluronic Acid and Its DerivativesOpenPubMed - Crosslinked Hyaluronic Acid in DermatologyOpenEuropean Commission Cosmetic Ingredient Database (CosIng)Open

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.