Ingredient review
Sodium Undecylenoamphoacetate
INCI: Sodium Undecylenoamphoacetate
A gentle, amphoteric surfactant that cleans effectively without stripping the skin, often used in sensitive-skin and baby formulations.
In plain English
Sodium Undecylenoamphoacetate is a mild cleansing ingredient that helps remove dirt and oil from your skin without leaving it feeling tight or dry. It is made from castor oil and is often used in products for sensitive skin or babies because it is very gentle. It also has some natural antimicrobial properties, which can help keep the skin clean.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
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
Useful, but context matters
Sodium Undecylenoamphoacetate 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 Undecylenoamphoacetate.
- 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 Undecylenoamphoacetate is an amphoteric surfactant, meaning it can work in both acidic and alkaline environments. It is derived from undecylenic acid, which comes from castor oil, and is known for its mildness and compatibility with other cleansing agents.
How it works
In a cosmetic product, this ingredient reduces the surface tension between water and oils, allowing dirt and excess sebum to be rinsed away. Because it is amphoteric, it is less likely to irritate the skin compared to harsher surfactants like sodium lauryl sulfate. It also has mild antimicrobial activity, which can help reduce bacteria on the skin's surface.
Pros
Very gentle on skin
Its amphoteric nature means it cleans effectively without disrupting the skin's moisture barrier, making it ideal for daily use on sensitive or dry skin.
Mild antimicrobial boost
The undecylenic acid backbone provides natural antimicrobial activity, which can help keep the skin clean and reduce odor-causing bacteria without harsh chemicals.
Cons and cautions
Lower foam volume
Compared to sulfates, this ingredient produces less foam, which some users may perceive as less effective, though it still cleans thoroughly.
Higher cost
As a specialty amphoteric surfactant, it is typically more expensive than common cleansers, which can increase the product price.
Best for
- People with sensitive or easily irritated skin
- Those looking for a gentle, non-stripping cleanser
- Parents seeking mild baby washes and shampoos
Use caution if
- Individuals with known allergies to castor oil derivatives (rare)
Usage tips
Safety summary
Sodium Undecylenoamphoacetate has a low irritation and comedogenic risk, making it safe for most skin types, including sensitive and baby skin. No significant safety concerns have been reported in cosmetic use.
Research notes
Research supports its mildness and antimicrobial properties, with studies showing it is less irritating than traditional anionic surfactants. However, more independent clinical data on long-term use is limited.
Common label clues
- Typical concentration
- 1–10% in rinse-off products
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. Generally recognized as safe when used as directed.
- Common uses
- Facial cleansers, Body washes, Shampoos, Baby care products
- Environmental note
- Derived from renewable castor oil and considered biodegradable, making it a more sustainable choice compared to petroleum-based surfactants.
Good to know
- This ingredient is often listed alongside other surfactants in the ingredient list.
- It is considered biodegradable and environmentally friendly compared to some synthetic surfactants.
Common questions
What is Sodium Undecylenoamphoacetate in beauty products?
Sodium Undecylenoamphoacetate is a mild cleansing ingredient that helps remove dirt and oil from your skin without leaving it feeling tight or dry. It is made from castor oil and is often used in products for sensitive skin or babies because it is very gentle. It also has some natural antimicrobial properties, which can help keep the skin clean.
What does Sodium Undecylenoamphoacetate do in a beauty product?
In a cosmetic product, this ingredient reduces the surface tension between water and oils, allowing dirt and excess sebum to be rinsed away. Because it is amphoteric, it is less likely to irritate the skin compared to harsher surfactants like sodium lauryl sulfate. It also has mild antimicrobial activity, which can help reduce bacteria on the skin's surface.
Is Sodium Undecylenoamphoacetate safe for most people?
Sodium Undecylenoamphoacetate has a low irritation and comedogenic risk, making it safe for most skin types, including sensitive and baby skin. No significant safety concerns have been reported in cosmetic use.
Who should be careful with Sodium Undecylenoamphoacetate?
Individuals with known allergies to castor oil derivatives (rare)
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.