Flavonoids, the key active compounds in Epimedii Folium, have both protective and toxic effects on the liver. Their hepatoprotective effects are associated with reducing lipid accumulation and oxidative stress, which contribute to the management of various liver conditions. In contrast, the mechanisms driving Epimedii Folium-induced hepatotoxicity are less understood but likely involve oxidative stress and pyroptosis. Pharmacokinetic studies, especially on icaritin, indicate that it undergoes isopentenyl dehydrogenation, glycosylation, and glucuronidation in vivo, contributing to its pharmacological effects. However, intermediate metabolites of icaritin may interact with biomolecules, potentially leading to liver toxicity. This review offers a detailed examination of the dual effects of Epimedii Folium flavonoids on liver function, emphasizing recent discoveries in their hepatoprotective and hepatotoxic pathways. We also summarize and discuss the pharmacokinetics of these flavonoids, highlighting how their metabolism affects therapeutic efficacy and toxicity. Lastly, we propose strategies to mitigate liver injury, providing new perspectives on the safe use of Epimedii Folium.