Undecylenamidopropyltrimonium Methosulfate

What is Undecylenamidopropyltrimonium Methosulfate?

Undecylenamidopropyltrimonium Methosulfate is a quaternary ammonium salt synthesized from undecylenic acid, an eleven-carbon unsaturated fatty acid derived from castor oil. Through amidation with propylamine and subsequent quaternization with a trimethylammonium group and methosulfate counterion, it becomes a water-soluble cationic surfactant. Commonly found in rinse-off hair care products like conditioners and shampoos, it works by electrostatically binding to the negatively charged keratin surface of hair fibers. This interaction neutralizes electrical charge buildup, minimizes inter-fiber friction, and forms a protective film that enhances tactile properties. The undecylenic chain also imparts subtle antimicrobial activity, aiding in formula stability. Its non-comedogenic nature makes it compatible with scalp use, supporting overall product performance in styling aids.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 3 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Antistatic agent
Reduces static electricity and flyaways by improving surface conductivity, enhancing hair manageability and smoothness in conditioners and styling products.
Hair conditioning
Improves softness, shine, and manageability by reducing friction and static; commonly achieved with cationic agents, silicones, oils, or conditioning polymers.
Antimicrobial agent
Helps limit growth of bacteria and other microbes on skin or in the formula; may be used for product protection, odor control, or targeted antimicrobial effects.

Benefits

Minimizes static electricity for easier hair detangling and styling.

Enhances hair smoothness and softness by reducing surface friction.

Offers supportive antimicrobial properties for product integrity.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
People with dry, frizzy, or static-prone hair.
Those sensitive to cationic surfactants.
Individuals seeking gentle conditioning in rinse-off formulas.
People with allergies to fatty acid derivatives.
Users preferring non-comedogenic ingredients for scalp application.
Individuals opting for preservative-free products.

Safety Notes

  • EWG score of 3 indicates moderate concern with limited data availability.
  • Non-comedogenic rating of 0 supports use on blemish-prone skin.

Frequently Asked Questions about Undecylenamidopropyltrimonium Methosulfate

What is its main function in hair products?

It serves as an antistatic and conditioning agent, improving manageability by reducing static and friction.

Is it suitable for acne-prone skin?

Yes, with a comedogenic rating of 0, it does not clog pores.

Does it have antimicrobial properties?

Yes, it helps limit microbial growth, supporting product preservation.