Humans excrete cypermethrin rapidly. Men who voluntarily ingested low doses of cypermethrin (0.25, 0.5, 1, or 1.5 milligrams per kilogram of body weight or mg/kg) in corn oil excreted between 49 to 78 percent of cypermethrin within 24 hours (1). These studies, along with results from animal studies, indicate that cypermethrin is unlikely to accumulate in the body.