What it is
Sodium cocoyl sarcosinate is the sodium salt of the amide formed between coconut-derived fatty acids and sarcosine (N-methylglycine). It is a gentle, biodegradable surfactant valued for foaming and cleansing with relatively low irritation compared with harsher sulfates. In sunscreens it appears at low levels to aid wetting, emulsification, and overall texture.
Safety & warnings
Considered a mild surfactant that is generally well tolerated, though like most cleansing agents it can be drying or mildly irritating at high concentrations. It is not a recognized fragrance allergen and is non-comedogenic at typical use levels.
Origin & sourcing
Derived from coconut-sourced fatty acids combined with sarcosine, an amino-acid derivative; the finished material is produced synthetically.
Questions everyone asks
Is sodium cocoyl sarcosinate harsh?
It is regarded as one of the milder anionic surfactants, gentler than sulfate cleansers, though very high levels can still be drying.
Why is a surfactant in a sunscreen?
At low levels it helps wet and emulsify ingredients so the formula stays uniform and spreads evenly.