An arthritis pill could regrow scalp hair

The drug is upadacitinib, sold by AbbVie as Rinvoq. It is a selective JAK1 inhibitor already approved for rheumatoid arthritis, atopic dermatitis, ulcerative colitis, Crohn's disease and psoriatic arthritis.

JAK inhibitors like upadacitinib work by blocking certain enzymes in order to support the immune system and reduce inflammation. In alopecia areata, overactive JAK signalling drives immune cells to attack hair follicles. Using a JAK1 inhibitor, at least in theory, dampens these attacks and gives follicles breathing room to resume growing.

In a randomized pool of 1,399 study participants, all with severe alopecia areata - defined as at least 50 percent scalp hair loss - and an average loss at baseline of 84 percent, participants were assigned by a ratio of 2:2:1 to receive either 15mg upadacitinib, 30mg, or a placebo once daily for the next 24 weeks. This was followed by a 28-week blinded extension.

Those on the 15mg dose saw 45.2 and 44.6 percent of patients return to at least 80 percent scalp coverage by 24 weeks. On 30mg, 55 and 54.3 percent of patients had a similar effect. Only 1.5 percent and 3.4 percent of patients on placebo exhibited similar reactions.

In the 15mg and 30mg groupings, only around 14 percent and 20 percent of study participants achieved full regrowth, respectively.

Upadacitinib is the first JAK inhibitor to hit complete regrowth as a ranked secondary endpoint in a Phase 3 programme.

Most patients on the higher dose also regrew eyebrows and eyelashes, and anxiety, depression and quality-of-life measures improved. Separation from placebo was visible by week 8, and response rates were still climbing at week 24.

Three JAK inhibitors already have health regulator approvals for treating severe alopecia areata.

Baricitinib is able to recover 80 percent of scalp coverage for roughly 35 to 39 percent of patients. Deuruxolitinib at 31 percent, and ritlecitinib at 23 percent.

Upadacitinib's near-50 percent range makes it the best potential JAK inhibitor for combating alopecia areata.

JAK inhibitors carry an FDA boxed warning covering serious infections, cardiovascular events, blood clots, cancer and death, drawn largely from older rheumatoid arthritis patients on long-term therapy. In the pooled 24-week data, serious adverse events occurred in 1.6 percent of patients on 15 mg and 2.3 percent on 30 mg, against 0.4 percent on placebo.

The most common events were upper respiratory infection, acne, raised creatine phosphokinase and nasopharyngitis. There were no deaths, no adjudicated major cardiovascular events and no malignancies in the 30 mg group. One venous thromboembolism and one breast cancer were reported on 15 mg, both in patients with pre-existing risk factors. Investigators identified no new safety signals.

The European Commission approved upadacitinib for severe alopecia areata in adults and adolescents 12 and over on July 29, 2026. AbbVie filed a supplemental New Drug Application with the FDA on April 28, 2026; no target action date has been announced, and standard review timelines point to a decision in early 2027.