A939572 is an orally available piperidine-aryl urea-based small molecule that inhibits stearoyl-CoA desaturase 1 (SCD1) with high potency (IC50 = 37 nM/hSCD1 and ﹤4 nM/mSCD1) with little hERG channel blockade activity (IC50 >100 µM). When administered in ob/ob mice, A939572 effectively reduces desaturation indices in vivo (18:0/18:1n9 ratio from 26.9 to 8.47 in liver; from 15.4 to 7.35 in plasma post 5-day 10 mg/kg bid p.o.). A939572 is a useful tool for probing SCD1-mediated physiological and pathological processes both in cultures (50 nM-10 µM) and in vivo (5-10 mg/kg i.p. or 10 mg/kg p.o. in mice).