What it is
Hydroxypropyl Methylcellulose Stearoxy Ether is a chemically modified cellulose polymer. According to ingredient databases it is the reaction product of stearyl glycidyl ether and hydroxypropyl methylcellulose, which attaches a long fatty (stearoxy) chain to the water-loving cellulose backbone. This gives the polymer both thickening ability and a fatty, oil-compatible portion, so it controls viscosity and helps structure the texture of creams, serums, sunscreens, and primers.
Origin & sourcing
It is derived from cellulose, a plant-based polysaccharide, which is first converted to hydroxypropyl methylcellulose and then reacted with stearyl glycidyl ether to graft on the long stearoxy side chain.
Questions everyone asks
What is Hydroxypropyl Methylcellulose Stearoxy Ether made from?
It is made from cellulose: hydroxypropyl methylcellulose is reacted with stearyl glycidyl ether to add a long fatty chain to the cellulose backbone.
What does it do in a sunscreen?
It controls viscosity and helps structure the formula, giving the product its thickness and a smooth, even texture.