Ingredient review
Sodium Octoxynol-9 Sulfate
INCI: SODIUM OCTOXYNOL-9 SULFATE
A synthetic surfactant that cleans effectively but may be drying or irritating for sensitive skin.
In plain English
Sodium Octoxynol-9 Sulfate is a man-made cleansing ingredient that helps water mix with oil and dirt so they can be rinsed away. It's similar to other sulfates like sodium lauryl sulfate, but it's less common in modern skincare. While it does a good job at removing excess oil and impurities, it can strip the skin's natural moisture barrier if used too often, especially for people with dry or sensitive skin.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Main practical flags: irritation is moderate; clogging risk is low.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- moderate
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Sodium Octoxynol-9 Sulfate can be useful, but watch for some irritation potential.
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 Octoxynol-9 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
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
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
A synthetic anionic surfactant derived from octoxynol, a type of alkylphenol ethoxylate, that has been sulfated and neutralized with sodium. It is primarily used as a cleansing agent in rinse-off products.
How it works
It reduces the surface tension between water and oil, allowing dirt, sebum, and makeup to be emulsified and washed away. Its sulfate group gives it strong foaming and cleansing properties.
Pros
Strong cleanser
Effectively removes excess oil, dirt, and some makeup, leaving skin feeling thoroughly clean.
Good lather
Creates a rich, foamy lather that many people associate with a satisfying cleansing experience.
Cons and cautions
Potential for dryness
Can strip the skin of its natural oils, leading to tightness, dryness, or irritation, especially with frequent use.
Not ideal for sensitive skin
May cause stinging or redness in those with compromised skin barriers or conditions like rosacea.
Best for
- People with oily or combination skin who need a deep cleanse
- Those who tolerate sulfates well and prefer a foamy lather
Use caution if
- Individuals with dry, sensitive, or eczema-prone skin
- Anyone looking for a sulfate-free or gentle cleansing routine
Usage tips
Safety summary
Generally considered safe for use in rinse-off cosmetics at typical concentrations, but it can be drying and irritating for sensitive skin types. Avoid contact with eyes.
Research notes
Limited peer-reviewed research specifically on Sodium Octoxynol-9 Sulfate in cosmetics. Its safety profile is inferred from related sulfates and surfactant studies, which indicate moderate irritation potential.
Common label clues
- Typical concentration
- Typically 1-10% in rinse-off products
- Regulatory status
- Approved for use in cosmetics in the US, EU, and many other regions, with no specific concentration restrictions for rinse-off products.
- Common uses
- Facial cleansers, Shampoos, Body washes
- Environmental note
- As an alkylphenol ethoxylate derivative, it may raise environmental persistence concerns, though it is less studied than other surfactants.
Good to know
- This ingredient is less common in modern 'gentle' or 'sulfate-free' formulations.
- It is often found in budget or industrial-grade cleansers rather than premium skincare.
Common questions
What is Sodium Octoxynol-9 Sulfate in beauty products?
Sodium Octoxynol-9 Sulfate is a man-made cleansing ingredient that helps water mix with oil and dirt so they can be rinsed away. It's similar to other sulfates like sodium lauryl sulfate, but it's less common in modern skincare. While it does a good job at removing excess oil and impurities, it can strip the skin's natural moisture barrier if used too often, especially for people with dry or sensitive skin.
What does Sodium Octoxynol-9 Sulfate do in a beauty product?
It reduces the surface tension between water and oil, allowing dirt, sebum, and makeup to be emulsified and washed away. Its sulfate group gives it strong foaming and cleansing properties.
Is Sodium Octoxynol-9 Sulfate safe for most people?
Generally considered safe for use in rinse-off cosmetics at typical concentrations, but it can be drying and irritating for sensitive skin types. Avoid contact with eyes.
Who should be careful with Sodium Octoxynol-9 Sulfate?
Individuals with dry, sensitive, or eczema-prone skin Anyone looking for a sulfate-free or gentle cleansing routine
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.