What it is
Stearamidopropyl dimethylamine lactate is formed by neutralizing stearamidopropyl dimethylamine, a stearic-acid-derived amidoamine, with lactic acid to give a water-dispersible cationic species. The positive charge lets it deposit onto and condition keratin surfaces while reducing static. It is more commonly associated with hair products but can appear in skin formulations for its conditioning and emulsion-supporting behavior.
Safety & warnings
Stearamidopropyl dimethylamine and its salts are generally regarded as well tolerated at the low levels used in cosmetics. As a cationic, amine-based conditioning agent it has some potential to cause irritation on compromised or sensitive skin, so use levels are kept modest.
Origin & sourcing
Synthetic; typically derived from stearic acid (often of vegetable or animal origin) reacted to form an amidoamine, then salified with lactic acid.
Questions everyone asks
What does stearamidopropyl dimethylamine lactate do?
It is a cationic conditioning and antistatic agent that deposits on keratin surfaces, smoothing them and reducing static, and can help support emulsions.
Is it a UV filter?
No. It does not absorb or reflect UV light and serves only a conditioning and formulation role in sunscreens.