Hair loss is not a side effect of Xeljanz (tofacitinib citrate), according to the results of clinical trials used to gain approval of the drug. During clinical development, hair loss was not reported as an adverse effect.

Xeljanz is a Janus kinase (JAK) inhibitor and disease modifying anti-rheumatic drug (DMARD), which works by suppressing the immune system. It has been approved by the US Food and Drug Administration (FDA) for use in the treatment of rheumatoid arthritis, psoriatic arthritis, polyarticular juvenile idiopathic arthritis (JIA), ankylosing spondylitis and ulcerative colitis.

Xeljanz is used to treat hair loss in patients with alopecia areata

Alopecia areata is an autoimmune disease that causes hair loss. A number of small clinical studies have investigated Xeljanz in patients with alopecia areata. Xeljanz has also been used off-label, meaning that it is not approved by the US FDA, to treat this condition.

Looking at the results from 20 patients with severe alopecia areata who took Xeljanz, researchers found that most patients experienced hair regrowth. The amount of regrowth observed ranged widely from 1 to 100 percent, but 25 percent of patients did achieve >90 percent improvement in their SALT - Severity of Alopecia Tool - score. The average time to regrowth was 3.85 months.

Four to five weeks after treatment with Xeljanz was stopped, hair shedding occurred. This was slightly shorter that the 10-12 weeks reported during other studies.