Ingredient review
Nonoxynol-9 Citrate
INCI: DINONOXYNOL-9 CITRATE
A synthetic surfactant that helps cleanse and stabilize formulas, but may be irritating for sensitive skin and is best suited for rinse-off products.
In plain English
Nonoxynol-9 Citrate is a synthetic ingredient that helps cleansers foam and mix oil and water together. It's a modified version of a common surfactant, made to be a bit gentler, but it can still be drying or irritating for some people, especially those with sensitive or compromised skin. You'll mostly find it in products you rinse off, like face washes and shampoos.
Review score
Safety, usefulness, and evidence
Useful in the right context, but not low-maintenance
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
Read the cautions before using
Nonoxynol-9 Citrate 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 Nonoxynol-9 Citrate.
- 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 surfactant and emulsifier derived from nonoxynol-9, modified with citric acid to potentially reduce irritation. It helps water and oil blend and creates foam in cleansers.
How it works
It lowers the surface tension between water and oil, allowing dirt, sebum, and makeup to be lifted away and rinsed off. As an emulsifier, it also helps keep oil and water-based ingredients mixed together in a stable formula.
Pros
Effective cleanser
Removes excess oil, dirt, and makeup efficiently, leaving skin feeling clean.
Formula stabilizer
Helps keep oil and water ingredients mixed, improving product texture and shelf life.
Cons and cautions
Potential irritation
May cause dryness, redness, or stinging for those with sensitive or compromised skin barriers.
Not for leave-on use
Best suited for rinse-off products; can be too harsh for leave-on formulations like creams or lotions.
Best for
- People with normal to oily skin looking for a thorough cleanse
- Those who use rinse-off products and do not have sensitive skin
Use caution if
- Individuals with very dry, sensitive, or eczema-prone skin
- Anyone looking for a completely non-irritating, gentle cleanser
Usage tips
Safety summary
Generally recognized as safe for use in rinse-off cosmetics at typical concentrations. However, it can be irritating for sensitive skin and may cause dryness with frequent use. Avoid contact with eyes and mucous membranes.
Research notes
Limited direct studies on Nonoxynol-9 Citrate specifically. Related nonoxynol compounds have been studied for surfactant properties and skin irritation potential. Evidence supports its use as a mild-to-moderate surfactant in rinse-off products.
Common label clues
- Typical concentration
- Typically used at 1–5% in rinse-off products
- Regulatory status
- Approved for use in cosmetics in the US and EU at concentrations typically up to 5% in rinse-off products. Always follow product instructions.
- Common uses
- Cleansers, Shampoos, Body washes
- Environmental note
- Nonoxynol-9 and its derivatives may have environmental persistence concerns; however, citrate modification may alter biodegradability. Check brand sustainability claims.
Good to know
- This ingredient is a modified version of nonoxynol-9, which has been studied for other uses but is generally considered safe in rinse-off cosmetics at low concentrations.
- It is not commonly found in 'gentle' or 'sensitive skin' labeled products.
Common questions
What is Nonoxynol-9 Citrate in beauty products?
Nonoxynol-9 Citrate is a synthetic ingredient that helps cleansers foam and mix oil and water together. It's a modified version of a common surfactant, made to be a bit gentler, but it can still be drying or irritating for some people, especially those with sensitive or compromised skin. You'll mostly find it in products you rinse off, like face washes and shampoos.
What does Nonoxynol-9 Citrate do in a beauty product?
It lowers the surface tension between water and oil, allowing dirt, sebum, and makeup to be lifted away and rinsed off. As an emulsifier, it also helps keep oil and water-based ingredients mixed together in a stable formula.
Is Nonoxynol-9 Citrate safe for most people?
Generally recognized as safe for use in rinse-off cosmetics at typical concentrations. However, it can be irritating for sensitive skin and may cause dryness with frequent use. Avoid contact with eyes and mucous membranes.
Who should be careful with Nonoxynol-9 Citrate?
Individuals with very dry, sensitive, or eczema-prone skin Anyone looking for a completely non-irritating, gentle cleanser
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.