ω-Hydroxy-DEET is a major metabolite of insect repellent N-N-diethyl-meta-toluamide (DEET). ω-Hydroxy-DEET has anti-proliferative effects. DEET is a spatial repellent and an irritant that commonly used to prevent contact with mosquitoes[2].In Vitro: Hepatoma cell studies reveals that ω-Hydroxy-DEET (DHMB; 0.1-10 μg/mL; 48-72 hours) treatments decreases cellular proliferation.In Vivo: The metabolite ω-Hydroxy-DEET (DHMB) is extensively distributed following intravenous and topical skin administration of DEET in rats. The ω-Hydroxy-DEET appeared to be the major metabolite for DEET. Repeated once-daily topical application for 30 days lead to higher concentrations of ω-Hydroxy-DEET in the liver.