Ingredient review

Sodium Undecylenoamphopropionate

INCI: Sodium Undecylenoamphopropionate

A gentle, plant-derived surfactant that cleanses without stripping the skin, making it a great choice for sensitive or dry skin types.

beautyskincarecleanser

In plain English

Sodium Undecylenoamphopropionate is a mild cleansing ingredient made from castor oil. It helps create a nice lather while being very gentle on the skin, so it won't leave your face feeling tight or dry. Think of it as a kinder alternative to harsh soaps that still gets the job done.

Review score

Safety, usefulness, and evidence

4.0Good
4.0/ 5

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
How reviews are scored

Quick decision guide

Useful, but context matters

Sodium Undecylenoamphopropionate 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Sodium Undecylenoamphopropionate.
  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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

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

An amphoteric surfactant, meaning it can work in both acidic and alkaline formulas. It is derived from undecylenic acid (a fatty acid from castor oil) and is known for its mildness and compatibility with other cleansing ingredients.

How it works

It reduces the surface tension between water and oil, allowing dirt, makeup, and excess sebum to be rinsed away. Because it is amphoteric, it is less irritating than many anionic surfactants (like SLS) and helps stabilize foam in a formula.

Pros

Very gentle on skin

Its amphoteric nature means it has low irritation potential, making it ideal for sensitive or reactive skin types.

Good foam booster

It helps create a rich, creamy lather in cleansers and body washes, improving the sensory experience without harshness.

Cons and cautions

Not a standalone heavy-duty cleanser

For removing waterproof makeup or heavy sunscreen, it works best when combined with other surfactants or oils.

May be less common in drugstore products

It is more often found in mid-range or natural-leaning brands, so it might not be in every budget cleanser.

Best for

  • People with dry or sensitive skin who find sulfates too harsh
  • Anyone looking for a milder, plant-derived cleanser

Use caution if

  • Those with a known allergy to castor oil derivatives (rare)
  • People who prefer completely sulfate-free formulas (though this is not a sulfate)

Usage tips

Use in rinse-off products like face washes and shampoos; it is not typically used in leave-on formulas.
Pair with a gentle oil cleanser or micellar water first if you wear heavy makeup, then follow with a product containing this surfactant.

Safety summary

Sodium Undecylenoamphopropionate is considered safe for use in cosmetics at typical concentrations. It has a low irritation and sensitization profile, and no significant safety concerns have been raised by regulatory or scientific bodies.

Research notes

While not as extensively studied as some common surfactants, available safety assessments and clinical data support its mildness and low irritation potential. It is recognized by the Cosmetics Ingredient Review (CIR) panel as safe in current usage patterns.

Common label clues

Typical concentration
1–10% in rinse-off products
Regulatory status
Approved for use in cosmetics in the US (FDA), EU, and most other regions. No specific restrictions beyond general cosmetic safety requirements.
Common uses
Facial cleansers, Body washes, Shampoos, Baby care products
Environmental note
Derived from castor oil, a renewable plant source. It is generally considered biodegradable, though specific environmental data may vary by formulation.

Good to know

  • It is often listed alongside other mild surfactants like Cocamidopropyl Betaine to create a balanced cleansing system.
  • Despite its long name, it is considered a 'green' ingredient because it comes from renewable castor oil.

Common questions

What is Sodium Undecylenoamphopropionate in beauty products?

Sodium Undecylenoamphopropionate is a mild cleansing ingredient made from castor oil. It helps create a nice lather while being very gentle on the skin, so it won't leave your face feeling tight or dry. Think of it as a kinder alternative to harsh soaps that still gets the job done.

What does Sodium Undecylenoamphopropionate do in a beauty product?

It reduces the surface tension between water and oil, allowing dirt, makeup, and excess sebum to be rinsed away. Because it is amphoteric, it is less irritating than many anionic surfactants (like SLS) and helps stabilize foam in a formula.

Is Sodium Undecylenoamphopropionate safe for most people?

Sodium Undecylenoamphopropionate is considered safe for use in cosmetics at typical concentrations. It has a low irritation and sensitization profile, and no significant safety concerns have been raised by regulatory or scientific bodies.

Who should be careful with Sodium Undecylenoamphopropionate?

Those with a known allergy to castor oil derivatives (rare) People who prefer completely sulfate-free formulas (though this is not a sulfate)

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.