Studies on the safety of herbal medicine are essential for the development of new drugs. The aim of this study was to evaluate the no-observed-adverse-effect-level (NOAEL) of HVC1 (Gamisamhwangsasim-tang, a 30% ethanol extract of a mixture of Pruni Cortex, Scutellariae Radix, Coptidis Rhizoma, and Rhei Rhizoma) and identify its target organs after oral administration to Sprague-Dawley (SD) rats repeatedly for 13 weeks. Three test groups were treated with HVC1 at a dose of either 500 (low-dose), 1,000 (middle-dose), or 2,000 (high-dose) mg/kg/day. Another group received high-dose HVC1 and was observed for 4 weeks following treatment to examine recovery from the effects of the extract. All treatment groups were compared to a vehicle control group. During the study, mortality, clinical signs, body weight changes, food consumption, abnormal lesions in the eye, urinary parameters, hematological parameters, blood coagulation time, blood biochemical parameters, changes in organ weight, gross findings, and histopathological changes were examined. No systemic toxicity related to HVC1 was observed in any group, and it was concluded that the NOAEL of HVC1 was 2,000 mg/kg/day. No target organ was identified.