JAK inhibitors are used to treat conditions such as rheumatoid arthritis, eczema, and alopecia areata. They also have other uses, such as myelofibrosis. These medications work by blocking Janus kinase (JAK) enzymes, which play a role in inflammatory processes in your body. JAK inhibitors come in different forms, including oral pills and topical creams. Examples include Xeljanz (tofacitinib), Olumiant (baricitinib), Cibinqo (abrocitinib), and more.