Isopropyl Isosterate
What is Isopropyl Isosterate?
A synthetic ester of isopropyl alcohol and isostearic acid, used as a light emollient in cosmetics.
Why is it used in products?
It provides excellent spreadability and a silky skin feel, making it popular in lightweight formulations.
Why does it clog pores?
Isopropyl isostearate is rated highly comedogenic in rabbit ear testing. Its branched-chain structure allows it to penetrate and accumulate inside pore openings, forming lipid plugs. Despite feeling light on the skin, it's one of the more reliably pore-clogging esters in cosmetic chemistry.
Commonly found in
- foundations
- moisturizers
- sunscreens
- primers