JAK Inhibitor Pills for Alopecia Areata: What Trials Found
HairArticleFor severe alopecia areata, daily JAK inhibitor pills are now approved in the US. In two large baricitinib trials, about 36% to 39% of adults on the higher dose had 80% or more of their scalp covered at 36 weeks, against 3% to 6% on placebo. A ritlecitinib trial found similar gains. Most people didn't reach that goal, and the drugs carry rare serious risks. Here is what the trials show.
Alopecia areata is an autoimmune condition that causes hair to fall out quickly from the scalp, eyebrows or eyelashes.1 For years, treatments for severe cases were limited.1 Now US regulators have approved three daily pills called JAK inhibitors: baricitinib and ritlecitinib for ages 12 and up, and deuruxolitinib for adults.2
How the trials measured success
The trials used a SALT score from 0 (no scalp hair loss) to 100 (complete loss).1 The goal was a score of 20 or less, meaning at least 80% of the scalp covered.1
Baricitinib
Two trials enrolled 1,200 adults with at least half their scalp hair gone.1
| At 36 weeks | Trial 1 | Trial 2 |
|---|---|---|
| 4 mg | 38.8%1 | 35.9%1 |
| 2 mg | 22.8%1 | 19.4%1 |
| Placebo | 6.2%1 | 3.3%1 |
- Acne, higher muscle enzyme levels and higher cholesterol were more common than on placebo.1
- At 52 weeks, about 37% to 41% on the 4 mg dose had reached the goal, though there was no placebo comparison by then.3 The authors suggested longer treatment may be needed for the full benefit.3
- The trials were funded by Eli Lilly.1
Ritlecitinib
A trial of 718 people, 62% of them female, tested several doses.4 At 24 weeks, 31% on the highest dose and 23% on 50 mg reached the goal, against 2% on placebo.4 Side effects were reported at similar rates across groups, and there were no deaths.4
What this means
- These pills help a meaningful minority regrow most of their hair, and some regrow eyebrows and eyelashes.2
- Most people in the trials didn’t reach 80% coverage within the first months.
- In trials for skin conditions, the most common side effects of JAK inhibitors were colds, bronchitis, ear and urinary infections, headache and nausea.5 A few people have had serious problems such as blood clots, pneumonia or tuberculosis.5
- Your dermatologist needs to know about smoking, heart disease, blood clots, high blood pressure, high cholesterol, diabetes, cancer and shingles.5
See what alopecia areata is and three questions about JAK inhibitors.
Try: “I’ve lost more than half my scalp hair to alopecia areata. Am I a candidate for a JAK inhibitor, how long should I give it, and what tests will I need?”
Hair, Everywhere covers patchy hair loss in Chapter 3, “Is This Just Vanity?,” in a section called “The Red-Flag List,” which sends a sudden round, smooth bald patch to a dermatologist. Its Hair Log keeps monthly photos with dates, so regrowth on any treatment can be judged against where you started. See the book.
This article is for general educational purposes only and is not medical advice. It isn't a substitute for diagnosis or treatment from a qualified healthcare professional who knows your health history. JAK inhibitors need a prescription, screening tests and monitoring. See a dermatologist for sudden patchy hair loss, and seek urgent care for chest pain, shortness of breath, leg swelling or signs of a serious infection while on treatment. Girl Playbook does not endorse any specific product, test, or provider.
Girl Playbook sells this book. It provides education and worksheets, not individualized medical care.
Sources
The research behind this article, in the order it’s cited. How we source our articles.
- New England Journal of Medicine (abstract via PubMed), 2022Two Phase 3 Trials of Baricitinib for Alopecia Areata (opens in a new tab)abcdefghijklm
- American Academy of Dermatology, treatment page, 2026Alopecia areata: Diagnosis and treatment (opens in a new tab)ab
- American Journal of Clinical Dermatology (abstract via PubMed), 2023Efficacy and Safety of Baricitinib in Patients with Severe Alopecia Areata over 52 Weeks of Continuous Therapy in Two Phase III Trials (BRAVE-AA1 and BRAVE-AA2) (opens in a new tab)ab
- Lancet journal (abstract via PubMed), 2023Efficacy and safety of ritlecitinib in adults and adolescents with alopecia areata: a randomised, double-blind, multicentre, phase 2b-3 trial (opens in a new tab)abc
- American Academy of Dermatology, JAK inhibitors page, 2026JAK inhibitors: What your dermatologist wants you to know (opens in a new tab)abc
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