Ingredient review

Stearyl Acetyl Glutaminate

INCI: Stearyl Acetyl Glutaminate

A mild, amino-acid-derived surfactant that cleanses without stripping the skin barrier, ideal for sensitive or dry skin.

beautyskincaresurfactant

In plain English

Stearyl Acetyl Glutaminate is a gentle cleansing ingredient made from a fatty alcohol (stearyl alcohol) and an amino acid (glutamine). Unlike harsh soaps that can strip your skin's natural oils, this ingredient helps lift dirt and oil while leaving skin feeling soft and hydrated. It's often used in creamy, non-foaming cleansers and moisturizers for sensitive skin.

Review score

Safety, usefulness, and evidence

4.2Good

4.2/ 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

Stearyl Acetyl Glutaminate 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 Stearyl Acetyl Glutaminate.
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

moderate

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

What it is

A semi-synthetic surfactant created by combining stearyl alcohol (a fatty alcohol from plant sources) with acetyl glutamine (a modified amino acid). It belongs to the class of amino-acid-based surfactants known for their mildness.

How it works

In a cosmetic product, Stearyl Acetyl Glutaminate acts as a surface-active agent. Its molecular structure has a water-loving head (from the amino acid) and an oil-loving tail (from the fatty alcohol). This allows it to surround and lift oil, dirt, and makeup from the skin so they can be rinsed away with water. Additionally, it deposits a thin conditioning film on the skin, reducing tightness and dryness after cleansing.

Pros

Ultra-gentle cleansing

This surfactant cleanses effectively without disrupting the skin's natural moisture barrier, making it ideal for daily use on sensitive or compromised skin.

Conditioning after-feel

Unlike many cleansers that leave skin tight, this ingredient leaves a soft, smooth finish that reduces the need for an immediate moisturizer.

Cons and cautions

Low foam volume

It produces a creamy, low-lather texture that may not satisfy users who associate foam with cleanliness, potentially leading to over-cleansing.

Limited makeup removal

On its own, it struggles to dissolve heavy, waterproof makeup or long-wear sunscreen, often requiring a double-cleansing routine.

Best for

People with dry, sensitive, or eczema-prone skin looking for a non-stripping cleanser
Anyone who prefers creamy, low-foam cleansers over high-foam ones

Use caution if

Those who require a high-foam, deep-cleansing experience for very oily skin may find it too mild

Usage tips

Use as part of a double-cleansing routine: follow an oil-based cleanser with a Stearyl Acetyl Glutaminate-based cleanser for thorough yet gentle removal.

Pair with a moisturizer if your skin feels dry after cleansing, though many users find it hydrating enough on its own.

Safety summary

Stearyl Acetyl Glutaminate is considered safe for use in cosmetics at typical concentrations. It has a low irritation and comedogenic risk, making it suitable for sensitive skin. No significant safety concerns have been reported in regulatory reviews.

Research notes

Amino-acid-based surfactants like Stearyl Acetyl Glutaminate are well-documented in cosmetic science for their mildness and skin compatibility. While direct clinical studies on this specific compound are limited, the broader class is supported by dermatological research showing reduced barrier disruption compared to traditional sulfates.

Common label clues

Typical concentration: 0.5–5% in rinse-off products; lower in leave-on formulas
Regulatory status: Approved for use in cosmetics in the EU, US, and other major markets. No known restrictions at typical usage levels.
Common uses: Facial cleansers, Body washes, Moisturizers, Shampoos
Environmental note: As a semi-synthetic ingredient, it is generally considered biodegradable and less harmful to aquatic life than some traditional surfactants, though specific environmental data is limited.

Good to know

It is often listed near the middle or end of an ingredient list because it is used at low concentrations.
This ingredient is compatible with other mild surfactants and is frequently found in sulfate-free formulations.

Common questions

What is Stearyl Acetyl Glutaminate in beauty products?

What does Stearyl Acetyl Glutaminate do in a beauty product?

Is Stearyl Acetyl Glutaminate safe for most people?

Who should be careful with Stearyl Acetyl Glutaminate?

Those who require a high-foam, deep-cleansing experience for very oily skin may find it too mild

Research sources

Cosmetic Ingredient Review (CIR) - Amino Acid SurfactantsOpen PubMed - Mild Surfactants and Skin BarrierOpen European Chemicals Agency (ECHA) - Stearyl Acetyl GlutaminateOpen

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.