Cleansing Agent

Undecylenamidopropyl Betaine

INCI: UNDECYLENAMIDOPROPYL BETAINE

Reviewed by Daisy · Last updated 14 Aug 2026

A mild surfactant that cleanses whilst conditioning skin and hair

Best For Skin Types

All, Sensitive, Combination, Oily

Addresses

Oil control, Sensitivity

Usage Frequency

Daily

What Is Undecylenamidopropyl Betaine?

Undecylenamidopropyl betaine is a synthetic surfactant derived from coconut oil fatty acids. It belongs to a class of ingredients called amphoteric surfactants, which means it carries both positive and negative charges. This dual nature allows it to work effectively across a broad pH range, making it a versatile choice in skincare and haircare formulations.

In cosmetics, this ingredient functions primarily as a cleanser and foaming agent. It helps to lift dirt, oils and impurities from the skin surface whilst maintaining a gentle profile. It also serves secondary roles as a conditioning agent and viscosity modifier, helping to thicken or stabilise formulations.

How It Works

Undecylenamidopropyl betaine works by reducing the surface tension between oil and water on the skin. One end of the molecule is attracted to oils (lipophilic), whilst the other is attracted to water (hydrophilic). This allows it to surround and suspend dirt particles and sebum, which are then rinsed away with water. The ingredient's amphoteric nature means it adapts its behaviour depending on the pH of the formulation, maintaining stability and efficacy across different product types.

The conditioning effect comes from the ingredient's ability to deposit a thin, protective film on the skin surface, which can help reduce moisture loss and improve the feel of the skin after cleansing.

Clinical Evidence & References

Research on undecylenamidopropyl betaine is limited in the context of routine skincare. Most available evidence examines its use in wound irrigation and antiseptic applications, where it has been studied alongside other agents. In these medical contexts, like other surfactants, it can affect skin cell behaviour at high concentrations—though formulation concentration and application context differ significantly from typical skincare products.

For general cleansing and conditioning benefits, the ingredient's safety profile is generally well-established in cosmetic use, though direct clinical trials specifically examining anti-ageing or therapeutic skin benefits are sparse. It is considered a mild, well-tolerated option compared to harsher surfactants.

How to Use

Undecylenamidopropyl betaine is most commonly found in cleansing products such as gentle face washes, micellar waters and body cleansers. Use as directed on the product label. For cleansing formulations, wet the skin, apply a small amount, massage gently, then rinse thoroughly with water. This ingredient works well in both rinse-off and leave-on formulations, depending on the product type.

Safety & Precautions

Undecylenamidopropyl betaine is generally well-tolerated and considered safe for cosmetic use at typical formulation levels. It is unlikely to cause irritation in most individuals, making it suitable for sensitive skin. However, as with any surfactant, concentrated forms may cause irritation if applied undiluted to skin or eyes.

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