Inhibiting ferroptosis represents a promising strategy to combat ferroptosis-related diseases. Here we show that 428, a selenide-containing noscapine derivative, effectively inhibits ferroptosis in various cell lines by enhancing the stability and activity of GPX4. TRIM41 was identified as a novel E3 ubiquitin ligase of GPX4 and 428 was demonstrated to bind to the selenocysteine residue Sec46 of GPX4 via the formation of a transient and reversible Se-Se bond, thereby blocking the interaction between GPX4 and TRIM41, stabilizing GPX4 and enhancing its activity. This unique dynamic covalent binding mode was preliminarily validated by structure-activity relationship analysis and molecular docking studies. Importantly, we demonstrated that 428 treatment alleviates bleomycin-induced pulmonary fibrosis in vivo by inhibiting ferroptosis. Overall, our studies identified a novel stabilizer and activator of GPX4, offering a potential therapeutic approach for the treatment of ferroptosis-related diseases and uncovering a new mechanism for regulating GPX4 degradation.