Encyclopedia · immunomodulator
Upadacitinib
A JAK1 pill already approved for other diseases that gave 45 to 55% of people with severe alopecia areata near-full scalp hair in two 2026 trials and is under regulatory review for hair.
What it is
Upadacitinib is an oral JAK1-selective inhibitor from AbbVie, sold as Rinvoq and approved for several inflammatory diseases. For alopecia areata it is not approved as of 10 October 2026. AbbVie announced a US submission in April 2026 for adults and adolescents and said the European regulator is also reviewing it. We found no approval decision. It is not relevant to pattern hair loss.
What the studies show
- Two replicate phase 3 trials (1,399 people aged 12 to 64 with at least 50% scalp loss) found at least 80% scalp hair at week 24 in 45.2% and 44.6% on 15 mg and 55.0% and 54.3% on 30 mg, versus 1.5% and 3.4% on placebo. The sponsor funded the trials (Mostaghimi 2026).
- These are the highest rates reported in a pivotal alopecia areata programme, but comparisons with other JAK drugs are indirect and trial populations differ (Mostaghimi 2026).
- The sponsor also reported complete regrowth at week 24 in about 14 to 22.5% on drug versus about 0 to 0.7% on placebo.
How it's used in studies
- 15 mg or 30 mg once daily for 24 weeks placebo-controlled, then a 28-week extension (Mostaghimi 2026).
Side effects and safety
- Common events in the programme were upper respiratory infection, acne, raised creatine phosphokinase and nasopharyngitis.
- Rinvoq's class labelling for other uses warns of serious infections, cancer, major cardiovascular events, clots and gastrointestinal perforation.
- The relapse-on-stopping seen with other JAK inhibitors is expected but not yet reported.
Bottom line
Upadacitinib has strong trial evidence of efficacy for severe alopecia areata but is still unapproved for hair, so watch for the regulators' decisions. Long-term safety at 30 mg is unknown. See JAK inhibitors and hair for the comparison. Discuss with a doctor.
Studies 1
Mostaghimi A et al. Upadacitinib for severe alopecia areata in adults and adolescents: two phase 3 UP-AA randomized clinical trials. JAMA Dermatol. 2026
Tested: upadacitinib 15 mg or 30 mg daily vs placebo
Result: At least 80% scalp hair at week 24 in 45.2% and 44.6% (15 mg), 55.0% and 54.3% (30 mg) vs 1.5% and 3.4% on placebo; sponsor-funded.
Read the study ↗Related
- BaricitinibA once-daily pill that was the first drug approved for severe alopecia areata, regrowing hair in about a third of patients while they keep taking it.
- RitlecitinibA once-daily pill approved for severe alopecia areata from age 12, which regrows hair in about 1 in 4 people by 6 months and keeps improving for years.
- DeuruxolitinibA twice-daily JAK pill approved in the US in 2024 for adults with severe alopecia areata, giving about 3 in 10 people near-full scalp hair at 24 weeks.
- TofacitinibThe first JAK inhibitor used off-label for alopecia areata; about a third to two thirds of patients regrow hair in open-label studies, but most relapse within months of stopping.
- JAK inhibitors and hairJanus kinase (JAK) inhibitors are pills that regrow hair in severe alopecia areata, but they are not treatments for ordinary pattern thinning.
- Hair growth pipeline (2026)What is in clinical trials for hair loss as of October 2026, how far along it is, and how much to trust the early numbers.