A 13-week dermal toxicity test was conducted to assess the toxicity of DA-5018, a capsaicin derivative. Three groups of Sprague-Dawley rats (10-15 males and 10-15 females) were treated with DA-5018 cream daily by dermal application at concentrations of 0.1%, 0.3% or 0.9% as 500 mg/kg for 13 weeks. One further group of rats (15 males and 15 females) received cream base at 500 mg/kg/day and acted as controls. One male receiving 0.3% DA-5018 cream died during the treatment period. But the animal did not show any signs of treatment-related toxicity until death. There were no local skin reaction of application site and systemic reaction to the treatment of DA-5018 creams in all experimental groups throughout treatment and recovery period. Weight gain and food consumption in animals that received DA-5018 creams appeared to be comparable to that of the controls. Laboratory analyses (hematology, urinalysis and opthalmoscopic examination) did not revealed pathological values. In biochemical investigations, an increase of glucose level associated with increased food consumption and some other significant changes were noted in the animals of both sexes received DA-5018 creams. But these changes were not considered to be of toxicological importance. Postmortem examination did not show macroscopic or histological alterations attributable to the DA-5018 treatments. Based on these results, NOAEL(no-observable-adverse-effect level) of DA-5018 cream if estimated to be over 500 mg/tg/day as 0.9% cream.