Ingredient review

Sodium Carboxymethyl Dextran Acetate Sulfate

INCI: SODIUM CARBOXYMETHYL DEXTRAN ACETATE SULFATE

A gentle, semi-synthetic film-former that helps soothe and protect the skin without clogging pores.

beautyskincarefilm-former

In plain English

Sodium Carboxymethyl Dextran Acetate Sulfate is a modified sugar molecule (derived from dextran, which comes from bacteria) that has been chemically tweaked to help it form a thin, invisible film on your skin. This film can help lock in moisture and calm irritation, similar to how a light gel might feel. It's often used in serums and moisturizers for sensitive skin because it's very unlikely to cause breakouts or stinging.

Review score

Safety, usefulness, and evidence

3.8Good

3.8/ 5

Potentially useful with some tradeoffs

The evidence base is still emerging, so marketing claims deserve extra caution.

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

Source: semi synthetic
Evidence: emerging
Irritation: low
Clogging risk: low

How reviews are scored

Quick decision guide

Useful, but context matters

Sodium Carboxymethyl Dextran Acetate Sulfate 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.

Step 1Start with the score, then check the irritation and clogging risk before judging Sodium Carboxymethyl Dextran Acetate Sulfate.
Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
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

emerging

The ingredient may be promising, but claims should be treated more cautiously.

What it is

A semi-synthetic polymer derived from dextran, a natural polysaccharide produced by certain bacteria. It has been chemically modified with carboxymethyl, acetate, and sulfate groups to enhance its film-forming and soothing abilities.

How it works

When applied to the skin, it forms a flexible, breathable film that helps reduce water loss (transepidermal water loss, or TEWL) and creates a protective barrier. The sulfate groups may also help calm inflammation by interacting with skin cells, though the exact mechanism is still being studied.

Pros

Gentle on sensitive skin

Its low irritation and comedogenic risk make it a safe choice for reactive or acne-prone skin types.

Lightweight protection

Creates a breathable film that helps retain moisture without feeling heavy or sticky, ideal under makeup.

Cons and cautions

Limited research

Compared to more common ingredients like hyaluronic acid, there are fewer studies on its long-term efficacy and safety.

Variable performance

Its film-forming and soothing effects can vary widely depending on the product formulation and concentration used.

Best for

People with sensitive or easily irritated skin
Those looking for a lightweight, non-comedogenic moisturizer or serum

Use caution if

Individuals with a known allergy to dextran (extremely rare)
Those seeking a heavy occlusive barrier (e.g., petrolatum) for very dry skin

Usage tips

Apply to damp skin to help the film form evenly and lock in more moisture.

Use after water-based serums and before heavier creams or oils for best layering.

Safety summary

Sodium Carboxymethyl Dextran Acetate Sulfate is considered safe for topical use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk, making it suitable for sensitive skin. However, long-term studies are limited, and allergic reactions are possible but very rare.

Research notes

Research on this specific ingredient is emerging. Most evidence comes from studies on related dextran derivatives, which show film-forming and anti-inflammatory properties. More peer-reviewed studies are needed to fully confirm its benefits and safety profile.

Common label clues

Typical concentration: 0.1% to 2%
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
Environmental note: Derived from bacterial fermentation (dextran) and chemically modified; the environmental impact is considered low compared to some petrochemical-based film-formers.

Good to know

This ingredient is often found in 'clean beauty' or sensitive-skin lines due to its gentle profile.
It is not a humectant like hyaluronic acid, but rather a film-former that helps seal in other ingredients.

Common questions

What is Sodium Carboxymethyl Dextran Acetate Sulfate in beauty products?

What does Sodium Carboxymethyl Dextran Acetate Sulfate do in a beauty product?

Is Sodium Carboxymethyl Dextran Acetate Sulfate safe for most people?

Who should be careful with Sodium Carboxymethyl Dextran Acetate Sulfate?

Individuals with a known allergy to dextran (extremely rare) Those seeking a heavy occlusive barrier (e.g., petrolatum) for very dry skin

Research sources

Cosmetic Ingredient Review (CIR) - Dextran Derivatives SafetyOpen PubMed - Dextran Sulfate Anti-inflammatory EffectsOpen INCI Database - Sodium Carboxymethyl Dextran Acetate SulfateOpen

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.