Sodium Stearate

Cleansing/emulsifying agent

Can be used to adjust the viscosity and stiffness of a formulation

May also lend itself waterproofing qualities

Often used in solid-style products such as stick-based sunscreens, bar soaps, and waxes

May potentially contribute to a pore-clogging residue on skin (depending on the overall formula)

Sodium stearate is a cleansing/emulsifying agent that can also be used to adjust the viscosity of cosmetic formulations. It is used as a gelling agent for solid products such as stick-style sunscreens and helps increase the stiffness of bar soaps and waxes. It may also lend itself to waterproofing qualities.

Worth noting, research indicates that sodium stearate can leave a residue, which could potentially clog pores. Another issue, generally speaking, is that bar cleansers/soaps tend to be drying on skin (although it depends on the exact composition of the formula).

Sodium stearate can be synthetically made or animal derived. It is supplied as a white powder in its raw material form.

In their 2019 report, the Cosmetic Ingredient Review (CIR) Expert Panel concluded that sodium stearate is safe in the present practices of use and concentration described in their assessment when formulated to be non-irritating and non-sensitizing. Their report looked at personal care products containing 0.000075–84% concentration of this ingredient.

See: Soap