Ingredient review
Undecylenamidopropyl Betaine
INCI: Undecylenamidopropyl Betaine
A gentle, low-irritation surfactant that cleanses without stripping the skin, often used in sensitive-skin and baby formulas.
In plain English
Undecylenamidopropyl Betaine is a mild cleansing ingredient derived from castor oil. It helps create a rich lather and remove dirt and oil from skin and hair, but it is much gentler than traditional sulfates like SLS. Because it is so mild, it is commonly found in products for sensitive skin, dry skin, and babies.
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
Undecylenamidopropyl Betaine 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 Undecylenamidopropyl Betaine.
- 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
A semi-synthetic surfactant made from undecylenic acid (a fatty acid from castor oil) and betaine (a natural amino acid derivative). It belongs to the betaine family of amphoteric surfactants, meaning it can work in both acidic and alkaline formulas.
How it works
It reduces the surface tension between water and oil, allowing dirt and sebum to be rinsed away. Its amphoteric nature makes it less irritating than anionic surfactants (like SLS) because it is less likely to strip the skin's natural moisture barrier.
Pros
Very gentle on skin
Its amphoteric structure means it is much less likely to cause irritation or dryness compared to common sulfates, making it ideal for sensitive skin and daily use.
Good foam quality
It produces a rich, creamy lather that feels pleasant during cleansing, without the harshness of stronger surfactants.
Cons and cautions
Milder cleansing power
For very oily skin or heavy makeup, it may not remove all residue on its own and is often blended with other surfactants.
Potential for slight dryness at high levels
In formulas where it is used above 10%, some users with very dry skin may notice mild tightness.
Best for
- People with sensitive or dry skin
- Those looking for sulfate-free cleansers
- Parents choosing baby washes
Use caution if
- Individuals with known castor oil allergy (rare)
- Those needing a very deep-cleansing formula for heavy makeup or oil
Usage tips
Safety summary
Undecylenamidopropyl Betaine is considered safe for use in rinse-off cosmetics at typical concentrations. It has a low irritation and sensitization profile, and no significant health concerns have been identified in cosmetic use.
Research notes
Studies and safety reviews by the Cosmetic Ingredient Review (CIR) panel have concluded that betaine-based surfactants like this one are safe in cosmetic formulations. Research shows they are mild to the skin and eyes, with low potential for allergic reactions.
Common label clues
- Typical concentration
- 1–10% in rinse-off products
- Regulatory status
- Approved for use in cosmetics in the EU, USA, and most 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 is biodegradable, making it a more sustainable choice compared to petroleum-based surfactants.
Good to know
- It is often used alongside Cocamidopropyl Betaine to boost foam and reduce irritation
- It is biodegradable and considered environmentally friendlier than some synthetic surfactants
Common questions
What is Undecylenamidopropyl Betaine in beauty products?
Undecylenamidopropyl Betaine is a mild cleansing ingredient derived from castor oil. It helps create a rich lather and remove dirt and oil from skin and hair, but it is much gentler than traditional sulfates like SLS. Because it is so mild, it is commonly found in products for sensitive skin, dry skin, and babies.
What does Undecylenamidopropyl Betaine do in a beauty product?
It reduces the surface tension between water and oil, allowing dirt and sebum to be rinsed away. Its amphoteric nature makes it less irritating than anionic surfactants (like SLS) because it is less likely to strip the skin's natural moisture barrier.
Is Undecylenamidopropyl Betaine safe for most people?
Undecylenamidopropyl Betaine is considered safe for use in rinse-off cosmetics at typical concentrations. It has a low irritation and sensitization profile, and no significant health concerns have been identified in cosmetic use.
Who should be careful with Undecylenamidopropyl Betaine?
Individuals with known castor oil allergy (rare) Those needing a very deep-cleansing formula for heavy makeup or oil
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.