Stearic Acid
AKA: Octadecanoic acid, 57-11-4, N-Octadecanoic acid, Stearophanic acid, Stearex Beads, Cetylacetic acid, 1-Heptadecanecarboxylic acid, Pearl stearic, Industrene R
Plant-Derived
Cleanser
Emulsifier
Plant Oil
Acid
Clean
Octadecanoic acid is a C18 straight-chain saturated fatty acid component of many animal and vegetable lipids. As well as in the diet, it is used in hardening soaps, softening plastics and in making cosmetics, candles and plastics. It has a role as a plant metabolite, a human metabolite, a Daphnia magna metabolite and an algal metabolite. It is a long-chain fatty acid, a saturated fatty acid and a straight-chain saturated fatty acid. It is a conjugate acid of an octadecanoate. It derives from a hydride of an octadecane.
Solubility 1 to 10 mg/mL at 73 °F (NTP, 1992)
Formula
C18H36O2
Mol. Weight
284.50
CAS #
57-11-4
Form
Liquid
Functions
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emulsion Stabilising
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Refatting
Cleansing
Makes oil and water mix so dirt, makeup, and sunscreen can actually be washed away. The reason your face wash foams.
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Surfactant Emulsifying
Skin Types
●all-skin-types, gentle
The paper trail
🔬Peer-reviewed1 paper →
⚖️Regulatory1 listing →
🛡️Safety-assessed3 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR