Ingredient review
Sodium Stearyl Fumarate
INCI: SODIUM STEARYL FUMARATE
A mild, plant-derived emulsifier that helps create stable, creamy textures with very low irritation potential.
In plain English
Sodium Stearyl Fumarate is a helper ingredient that allows water and oil to mix together smoothly in creams and lotions. It is made from stearyl alcohol (a fatty alcohol from plants) and fumaric acid (a natural acid found in plants). Because it is very gentle, it is often used in products for sensitive skin.
Review score
Safety, usefulness, and evidence
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
Quick decision guide
Easy yes for most routines
Sodium Stearyl Fumarate 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 Stearyl Fumarate.
- 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
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Sodium Stearyl Fumarate is a semi-synthetic emulsifier formed by combining stearyl alcohol (from plant sources like coconut or palm) with fumaric acid, then neutralizing with sodium. It is a white powder that helps stabilize emulsions.
How it works
In a cosmetic formula, Sodium Stearyl Fumarate sits at the boundary between oil and water droplets, reducing surface tension so they can mix into a stable, uniform cream or lotion. It also helps maintain the product's texture over time, preventing separation.
Pros
Gentle on skin
Sodium Stearyl Fumarate has a very low irritation risk, making it a good choice for sensitive or compromised skin barriers.
Stable texture
It helps creams and lotions maintain a consistent, smooth feel without separating over time, improving the user experience.
Cons and cautions
Sustainability concerns
The stearyl alcohol component is often derived from palm oil, which can be linked to deforestation unless certified sustainable.
Less widely used
Compared to common emulsifiers like cetearyl alcohol, Sodium Stearyl Fumarate appears in fewer products, so it may be harder to find.
Best for
- People with sensitive or reactive skin looking for gentle moisturizers
- Anyone who prefers products with mild, non-irritating emulsifiers
Use caution if
- Those seeking exclusively natural or organic formulations (it is semi-synthetic)
Usage tips
Safety summary
Sodium Stearyl Fumarate is considered safe for cosmetic use with very low irritation and sensitization potential. It is not known to be comedogenic and is well-tolerated even by sensitive skin.
Research notes
Safety assessments by the Cosmetic Ingredient Review panel and European Commission support its use as a mild emulsifier. No significant toxicity or irritation concerns have been raised in published literature.
Common label clues
- Typical concentration
- 0.5% to 3%
- Regulatory status
- Approved for use in cosmetics by the European Commission (CosIng) and generally recognized as safe by the U.S. Cosmetic Ingredient Review panel.
- Common uses
- Moisturizers, Creams, Lotions, Sunscreens
- Environmental note
- The stearyl alcohol source may be palm oil; choosing products with RSPO-certified palm oil can reduce environmental impact.
Good to know
- Sodium Stearyl Fumarate is approved by the CosIng database of the European Commission as a safe cosmetic ingredient.
- It is sometimes used in pharmaceutical creams for its mildness.
Common questions
What is Sodium Stearyl Fumarate in beauty products?
Sodium Stearyl Fumarate is a helper ingredient that allows water and oil to mix together smoothly in creams and lotions. It is made from stearyl alcohol (a fatty alcohol from plants) and fumaric acid (a natural acid found in plants). Because it is very gentle, it is often used in products for sensitive skin.
What does Sodium Stearyl Fumarate do in a beauty product?
In a cosmetic formula, Sodium Stearyl Fumarate sits at the boundary between oil and water droplets, reducing surface tension so they can mix into a stable, uniform cream or lotion. It also helps maintain the product's texture over time, preventing separation.
Is Sodium Stearyl Fumarate safe for most people?
Sodium Stearyl Fumarate is considered safe for cosmetic use with very low irritation and sensitization potential. It is not known to be comedogenic and is well-tolerated even by sensitive skin.
Who should be careful with Sodium Stearyl Fumarate?
Those seeking exclusively natural or organic formulations (it is semi-synthetic)
Research sources
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.