Magnesium Myristate

Magnesium Myristate is the magnesium salt of myristic acid, a saturated fatty acid that is naturally found in coconut and palm kernel oil.

In formulas, it's used as an anticaker, opacifier, and viscosity controller; it improves adhesion and glide in pressed mineral makeup, works as a non-gelling thickener in eyeliners/mascaras/lipsticks, and doubles as a white opacifier.

There's no published concentration use from surveys so the best available numbers are supplier guidance: 5-10% for loose powders and 2-5% for creamy cosmetics + pressed powder binding.

The CIR Expert Panel reviewed Magnesium Myristate as part of its assessment of myristic acid and its salts and esters, and concluded the whole group is safe as used in cosmetics.

In human studies, Myristic Acid was non-irritating up to 50% and 100% Magnesium Stearate was non-irritating and non-corrosive on skin and non-irritating to the eye.

There are no published contact allergy case reports for this ingredient so allergy risk is low, but not zero for any ingredient.

Comedogenicity

There is no comedogenic data for Magnesum Myristate. The comedogenic ratings that circulate for "myristates" come from Isopropyl Myristate which is a structurally different ester.

The rabbit-ear models those comedogenic ratings come from have been shown to be unreliable for predicting whether a finished product will clog pores.

Human testing has proved that any finished product with a comedogenic ingredient won't automatically make you break out; it really comes down to concentration, formula, and your skin.

Some people still find it breaks them out. So if that's you, definitely trust your skin.