Background: Korean red ginseng (KRG) has been shown to possess diverse biological effects, including anti-inflammatory and anti-allergic. KRG also exerts therapeutic effects against atopic dermatitis (AD) by reducing systemic inflammation. Objectives: We aimed to identify the synergistic effects of KRG on conventional therapeutic medicines in a mouse model of AD. Methods: NC/Nga mice with 2,4,6-trinitro-1-chrolobenzene (TNCB) induced AD-like skin lesions were divided into two large groups, one taking oral medication and the other applying topical agent. For the group with systemic feeding, evening primrose oil (EPO), cyclosporine, and hydroxyzine with or without KRG were administered orally by a gastric tube. For the topical group, topical desonide, tacrolimus hydrate 0.03%, diphenhydramine with or without oral KRG were applied. Results: SCORAD levels of hydroxyzine (P= 0.003), cyclosporine (P= 0.023), and EPO (P= 0.023) groups in oral formulations, and topical diphenhydramine (P= 0.003) were significantly reduced. The decrease in ear thickness of cyclosporine (P= 0.003) and EPO (P= 0.003) in oral, desonide (P= 0.003) and antihistamine (P= 0.003) in the topical group were statistically significant. The decrease in TEWL was statistically significant in cyclosporine (P= 0.007), topical desonide (P= 0.003), and antihistamine (P= 0.003). Conclusion: KRG extract showed synergistic effects of KRG extract on conventional therapeutic medicines in a mouse model of AD.