Ritlecitinib, a selective Janus kinase 3 (JAK3) and tyrosine kinase expressed in hepatocellular carcinoma (TEC) kinase family inhibitor, exhibits promising potential as an effective therapeutic modality for addressing alopecia areata and vitiligo. This section will comprehensively explore ritlecitinib, covering its molecular composition, pharmacokinetic and pharmacodynamic profiles, mechanism of action, and associated safety implications.