Anthocyanins are plant polyphenols widely regarded as antioxidants, yet they can exert concentration-dependent effects and act as pro-oxidants in specific contexts. Although their protective role in stressed testicular cells is established, their impact on Leydig cell steroidogenesis under non-pathological conditions remains poorly understood. Here, we investigated how an anthocyanin-enriched fraction from Callistemon citrinus (0–1.00 μg/mL) affects androgen synthesis in murine TM3 Leydig cells.