What it is
Methyl Diisopropyl Propionamide, commonly called WS-23, is a synthetic cooling agent in the same family as the menthol-derived coolants used in oral and personal-care products. Unlike menthol it imparts a cooling sensation with essentially no minty odor, which makes it useful where a fresh feel is wanted without scent. In sunscreens it is added to give an immediate cooling, refreshing skin feel on application.
Safety & warnings
WS-23 is generally well tolerated at the low levels used for a cooling effect, with no widely recognized allergenicity or comedogenicity concerns; very high concentrations could feel uncomfortable to sensitive skin, but typical cosmetic use is mild.
Origin & sourcing
Synthetic; manufactured as a defined cooling agent.
Questions everyone asks
What does WS-23 do in sunscreen?
It is a cooling agent that creates a fresh, cool sensation on the skin without adding a minty smell.
How is it different from menthol?
It produces a similar cooling feel but with essentially no odor or flavor, unlike menthol.