The objective of this study was to evaluate the anti-aging potential and skin safety of red ginseng (RG) and fermented red ginseng (FRG) using Lactobacillus brevis for use as cosmetic ingredients. Concentrations of uronic acid, polyphenols, and flavonoids, and antioxidant activities were greater in FRG compared to RG. The contents of total ginsenosides were not significantly different. However, the ginsenoside metabolite content was higher in FRG (14,914.3 μg/mL) compared to RG (5697.9 μg/mL). The tyrosinase inhibitory activity (IC(50)) of FRG was 27.63 μg/mL, and more potent compared with RG (34.14 μg/mL), (P<.05). The elastase inhibitory activity (IC(50)) of FRG was 117.07 μg/mL also higher compared with RG (157.90 μg/mL). In a primary skin irritation test, 10% RG and 10% FRG were classified as practically nonirritating materials. In a skin sensitization test, the RG group showed a sensitization rate of 100% and its mean evaluation score of irritation was 1.4, whereas the FRG group showed 20% and 0.2%, respectively. By fermentation of RG, FRG has increased contents of ginsenoside metabolites, such as Rg3, Rg5, Rk1, compound K, Rh1, F2, Rg2, and flavonoids content. Therefore, FRG offers increased anti-wrinkle efficacy, whitening efficacy, and reduced toxicological potency compared to RG.