Ingredient review

Ammonium Nonoxynol-4 Sulfate

INCI: AMMONIUM NONOXYNOL-4 SULFATE

A moderately effective synthetic cleanser that can be drying or irritating for sensitive skin, but is generally safe in rinse-off formulas.

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In plain English

Ammonium Nonoxynol-4 Sulfate is a man-made ingredient that helps water mix with oil and dirt so they can be rinsed away. It creates foam and lather in products like shampoo and body wash. Because it can strip natural oils, it may leave skin feeling tight or dry, especially if you have sensitive or dry skin.

Quick decision guide

Useful, but context matters

Ammonium Nonoxynol-4 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Ammonium Nonoxynol-4 Sulfate.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

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 synthetic anionic surfactant derived from nonoxynol, a type of nonionic surfactant, modified with a sulfate group and neutralized with ammonium. It is chemically similar to other sulfates used in cleansing.

How it works

It reduces the surface tension between water and oil, allowing oils and dirt to be lifted from the skin or hair and rinsed away. Its foaming action helps distribute the product and gives a sensory cue of cleanliness.

Pros

Strong cleanser

Effectively removes excess oil, dirt, and some water-resistant impurities, leaving skin feeling clean.

Good lather

Produces a rich, foamy lather that many people associate with a satisfying wash experience.

Cons and cautions

Potential irritation

Can cause dryness, tightness, or irritation, especially for those with sensitive or compromised skin barriers.

Strips natural oils

May remove too much of the skin's natural sebum, leading to imbalance and increased sensitivity over time.

Best for

  • People with normal to oily skin looking for a thorough cleanse
  • Those who prefer foaming cleansers and do not have sensitivity to sulfates

Use caution if

  • Individuals with dry, sensitive, or eczema-prone skin
  • Those following a sulfate-free or low-foam routine

Usage tips

Use only in rinse-off products and avoid leaving on skin for extended periods.
Follow with a moisturizer to replenish hydration after cleansing.
If irritation occurs, switch to a gentler sulfate-free cleanser.

Safety summary

Generally safe in rinse-off products at typical concentrations, but can be irritating for sensitive skin. Not associated with serious health risks when used as directed.

Research notes

Limited direct studies on this specific surfactant, but it is chemically similar to other alkyl sulfates which have been well-studied for skin irritation and cleansing efficacy.

Common label clues

Typical concentration
1–10% in rinse-off products
Regulatory status
Approved for use in cosmetics in the EU, US, and many other regions, with typical concentration limits for rinse-off products.
Common uses
Shampoos, Body washes, Facial cleansers
Environmental note
As a synthetic surfactant, it may have moderate aquatic toxicity; however, it is biodegradable under standard conditions.

Good to know

  • This ingredient is less common than Sodium Lauryl Sulfate but has similar cleansing properties.
  • It is often used in combination with milder surfactants to reduce irritation potential.

Common questions

What is Ammonium Nonoxynol-4 Sulfate in beauty products?

Ammonium Nonoxynol-4 Sulfate is a man-made ingredient that helps water mix with oil and dirt so they can be rinsed away. It creates foam and lather in products like shampoo and body wash. Because it can strip natural oils, it may leave skin feeling tight or dry, especially if you have sensitive or dry skin.

What does Ammonium Nonoxynol-4 Sulfate do in a beauty product?

It reduces the surface tension between water and oil, allowing oils and dirt to be lifted from the skin or hair and rinsed away. Its foaming action helps distribute the product and gives a sensory cue of cleanliness.

Is Ammonium Nonoxynol-4 Sulfate safe for most people?

Generally safe in rinse-off products at typical concentrations, but can be irritating for sensitive skin. Not associated with serious health risks when used as directed.

Who should be careful with Ammonium Nonoxynol-4 Sulfate?

Individuals with dry, sensitive, or eczema-prone skin Those following a sulfate-free or low-foam routine

Research sources

CosIng (EU Cosmetic Ingredient Database)OpenPubChem (NIH) - Ammonium Nonoxynol-4 SulfateOpenEnvironmental Working Group (EWG) Skin DeepOpen

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.