The biodistribution and metabolism of [8-14C]-octacosanol in rats were investigated to understand the mechanism of increased physical exercise and motor endurance by octacosanol. After 14C-octacosanol administered, radioactivity of octacosanol was mainly found in adipose tissue, especially in brown adipose tissue. Absorption of octacosanol is very low and mainly excreted through feces. The radioactivity of octacosanol was also partly expired as 14CO2. About 49% of the administered dose were excreted through different pathways. Metabolites of octacosanol are present in the urine. Octacosanol may be partly oxidized and degraded to fatty acids through β-oxidation