The diethanolamide of undecylenic acid, a multifunctional surfactant regulated in Annex III.
What it is
Undecylenamide DEA is N,N-bis(2-hydroxyethyl)undecenamide, the amide of undecylenic acid (an unsaturated C11 fatty acid) and diethanolamine. CosIng lists it as an anti-seborrhoeic, antimicrobial, antistatic, foam-boosting, hair-conditioning and viscosity-controlling ingredient. In the EU it is covered by an entry in Annex III (substances subject to restrictions) that limits the secondary amine content.
Where it is used
Appears on the ingredient lists of a small number of products, such as shampoos.
Limits of interpretation
The INCI list shows which ingredients are present, not how much of each. Above 1%, ingredients are listed in descending order of weight; below 1% the order is free.
See the EU regulation section for the applicable limits and conditions. The label does not show the concentration actually used.
Functions
- Anti-seborrheic
- Preventing or relieving the symptoms of seborrhea and/or seborrheic dermatitis, including dandruff.
- Antimicrobial
- Preventing and/or slowing down microbial growth.
- Antistatic
- Preventing and/or reducing static electricity by neutralising electrical charge on surfaces.
- Surfactant – foam boosting
- Increasing foaming capacity and/or stabilize foams in general.
- Hair conditioning
- Enhancing the appearance and feel of hair. Leaving the hair easy to comb, supple, soft and shiny and/or imparting volume, lightness, gloss, texture, etc.
- Viscosity controlling
- Increasing or decreasing the viscosity (thickness) of cosmetics.
EU regulation
- Maximum concentration
- Maximum secondary amine content: 0.5%
- As of
- 3 November 2026 · (EC) 2009/1223