Stearamidopropyl dimethylamine is used in cosmetic formulations as a conditioner and emulsifier. However, the emulsifying and conditioning effect is based on the cationic, i.e. protonated, form of the emulsifier. For this purpose, the water phase must be adjusted to a pH value of 4-5 before emulsification. As a guideline, one can take about 0.3 g of 80 % lactic acid per gram used. Stearamidopropyl dimethylamine itself is melted in the oil phase. During emulsification, the stearamidopropyl dimethylamine is then converted at the oil/water interface into its cationic, i.e. emulsifying and conditioning, form. This emulsifier/conditioner is mainly used in hair care, where it leads to better wet and dry combability, more shine and better grip, also thanks to its antistatic effect. In shampoos, it also has a viscosity-increasing effect. As a co-emulsifier, however, stearamidopropyl dimethylamine also improves the skin feel of creams and lotions.
Melting range: 
66-69 °C
 
Use concentration: 
1-3 % in hair conditioners and cures.
0.5-2 % in shampoos