What is Magnesium Stearate?
Magnesium Stearate is a mineral-based ingredient. A stearate salt used as a bulking and anti-caking agent in powders, rated 1/5.
Where Magnesium Stearate shows up
You'll most often find Magnesium Stearate in sunscreens, mineral makeup, and masks. Separately from clogging, its irritancy is rated 0/5 — low, so it's unlikely to sting or sensitise on its own.
Is Magnesium Stearate bad for acne-prone skin?
That low score makes Magnesium Stearate a reasonable choice even for acne-prone skin. As always, individual reactions vary, but it is not a likely cause of clogged pores.
Note for fungal-acne (malassezia) sufferers: Magnesium Stearate is commonly avoided in fungal-acne routines, since it falls into the fatty-acid or ester families the yeast can feed on. The evidence there is looser than for comedogenicity — see our fungal-acne checker for context.