Tristearin is a chemical compound from the group of simple triglycerides. All three hydroxy groups of glycerol are esterified with stearic acid. It was shown that in tristearin treated human umbilical vein smooth muscle cells (HUVSMCs), the saturated fatty acid content was increased, and the compositions of polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid were decreased significantly. Tristearin had significant promotion effects on the proliferation of HUVSMCs induced by oxidized‐LDL. Tristearin is a triacylglycerol commonly found in dietary fats. It increases serum cholesterol levels in rats. Tristearin is also used to form the lipid matrices of solid lipid nanoparticles. Formulations containing tristearin are used in cosmetic products to condition skin and as thickening agents.