When drugs are developed to treat a particular condition, often other unforeseen uses result—like use of baby aspirin for people at risk for heart attack. Tofacitinib citrate is a rheumatoid arthritis medication that has been found to re-grow hair.
Researchers at Yale University used the arthritis drug as an experimental treatment for alopecia universalis, a rare immune disease that results in complete loss of body hair. The cause of this disease is unknown, as is a cure.
A – Patient before treatment. B – Two months into treatment with tofacitinib. C – Three months into treatment. D – Eight months into treatment. YALE UNIVERSITY
Tofacitinib citrate was tested as a short-term treatment. Building on studies at Columbia University in which tofacitinib citrate and another JAK (Janus kinase) inhibitor ruxolitinib were successfully used to treat a similar disease called alopecia areata in mice , senior author Dr. Brett A. King is very enthusiastic:
“In addition to psoriasis, the patient reported a history of alopecia areata (AA) beginning around age two years, which progressed to alopecia universalis (AU) by age 18 years…To our knowledge, this is the first report of effective pathogenesis-based therapy for a patient with alopecia universalis. While the results in this patient are provocative…Given the potential for serious adverse effects from oral JAK inhibitors, it would be particularly useful to explore the use of topical formulations for these disorders…With every new agent, more thoughtful treatment algorithms become possible…This case highlights the interplay between advances in basic science and therapeutics and provides a compelling example of the ways in which an increasingly complex understanding of medicine and ingenuity in treatment benefit patients.” 
The subject of the study was a 25-year-old man; he approached the University’s School of Medicine to treat his chronic psoriasis. In just 3 months, there was significant re-growth of hair everywhere on the patient’s body—seven years after being diagnosed with AU.
The hair follicles aren’t dead as the result of this condition, they are prevented from growing new hair by the immune system. The JAK inhibitor tells the immune system that hair is okay. While there can be serious side effects of tofacitinib, the patient was carefully monitored but didn’t experience any. Dr. King plans to continue his research and has already submitted a proposal to study use of a topical formula of tofacitinib citrate to treat a similar but less advanced strain of alopecia.
So while the results of the research are very promising for several reasons, they are not to be construed as a cure for common baldness. We may be a long way away from that. It is very encouraging, though, as causes are found and corresponding treatments for related conditions progress to find new ways of using and building upon existing science.