xeljanz (tofacitinib) is a small pill, not an injection or infusion, for adults with moderate to severe ra for whom methotrexate did not work well. xeljanz is an ra medicine that can enter cells and disrupt jak pathways, thought to play a role in the inflammation that comes with ra. xeljanz can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections and cancers have happened in patients taking xeljanz. don't start xeljanz if you have any kind of infection, unless ok with your doctor. tears in the stomach or intestines, low blood cell counts and higher liver tests and cholesterol levels have happened. your doctor should perform blood tests before you start and while taking xeljanz, and routinely check certain liver tests. tell your doctor if you have been to a region where certain fungal infections are common, and if you have had tb, hepatitis b or c, or are prone to infections. tell your doctor about all the medicines you take, and if you are pregnant, or plan to be. taken twice daily,