Abstract: The present invention relates to methods and compositions for the treatment of autoimmune diseases and of excessive hair shedding or hair loss in a subject or for promoting hair growth in a subject wherein the subject has an autoimmune hair loss disorder, such as alopecia areata. The methods and compositions comprise the administration of a janus kinase inhibitor, such as tofacitinib, wherein the inhibitor is predominantly absorbed through the oral mucosal routes such as the sublingual mucosa.