A pill already sold for rheumatoid arthritis and other immune diseases helped many people with severe autoimmune hair loss grow their hair back in two large trials. The drug is upadacitinib, sold by AbbVie as Rinvoq. Results from two identical trials, together involving 1,399 people with alopecia areata, were published on August 12 in the journal JAMA Dermatology1. After 24 weeks, about half of the people taking the drug had most of their scalp covered with hair again, and some had all of it back2.
Alopecia areata happens when the immune system mistakenly attacks hair follicles. It affects around 2 percent of people worldwide2 and more than 7 million Americans3. The follicles are not permanently damaged, so the hair loss can be reversed, but stopping the immune attack is the hard part2.
What the trials tested
The two trials, run in parallel, enrolled people aged 12 to 64, including 118 teenagers. Everyone had lost at least half of their scalp hair2. On average, participants had lost about 84% of their scalp hair before they started1. The trials ran at 248 sites worldwide4, including hospitals in North America, Europe and China1, and took place between 2023 and 20253.
Each person was assigned by chance to take a daily pill containing either a lower dose of the drug, a higher dose, or a placebo (a dummy pill), for 24 weeks2. Neither the patients nor the doctors knew who got what, a design called double-blind4.
Hair loss was scored with a standard scale called SALT. The main goal was a score of 20 or lower, which means at least 80% of the scalp is covered with hair2.
The results so far
The numbers were similar in both trials2:
- Lower dose: 45.2% and 44.6% of people reached at least 80% scalp coverage.
- Higher dose: 55% and 54.3% reached it.
- Dummy pill: 1.5% and 3.4% reached it.
A stricter goal, at least 90% scalp coverage, was reached by 36% (lower dose) and 47.1% (higher dose) of people in the first trial, against 1.4% on the dummy pill5. In the second trial the figures were 35.2% and 45.8%, against 0.7%6.
Between 13% and 22.5% of people on the drug regrew all of their scalp hair, depending on the dose and the trial2. AbbVie says Rinvoq is the first drug of its type to meet the goal of complete scalp regrowth at 24 weeks in this kind of trial4.
The gap with the dummy pill showed up early. The researchers wrote that both doses met the main goal “beginning at week 8”2. Eyebrows and eyelashes also improved7, and people on the drug reported better quality of life2. According to the National Alopecia Areata Foundation, a patient group, hair regrowth kept improving through 52 weeks for people who stayed on the drug7.
Side effects reported
In the first trial, serious side effects affected 1.4% of people on the lower dose and 2.8% on the higher dose, compared with none on the dummy pill5. One person on the lower dose, who had several risk factors, developed a blood clot in a vein5. The most common side effects were acne, colds and upper airway infections5, along with a rise in a muscle-related blood marker called creatine phosphokinase6. AbbVie said no new safety concerns were found compared with the drug’s other uses6.
Good News Network’s summary of the published paper says one patient developed breast cancer after having worrying mammogram results before the trial began, and that no deaths were reported8.
Rinvoq belongs to a class of drugs called JAK inhibitors, which block signals the immune system uses to drive inflammation1. Drugs in this class can cause nausea and acne, and in rare cases can raise the risk of life-threatening problems such as heart attack and stroke3. Spencer Kobren, founder of the American Hair Loss Association, called the results “very encouraging” but warned about these risks3. He said:
There are patients who understand that these medications carry significant risks … and are still willing to accept them for the possibility of getting their hair back.
That quote was given to Healthline and reported by PhillyVoice3.
What it does not show yet
The main comparison lasted only 24 weeks, so longer-term effects and health risks are not yet known2. The researchers themselves say longer treatment and follow-up are needed to see how lasting the regrowth is and how the benefits weigh against the risks1. How much hair grew back, and how fast, varied from person to person1.
The trials compared the drug only with a dummy pill, not with other alopecia treatments already on the market2. The results also do not tell us what happens to hair if people stop taking the pill.
Who is behind it
AbbVie, which makes upadacitinib, funded and helped design the trials, and some of the study’s researchers are AbbVie employees2. The paper was peer reviewed, meaning outside experts checked it before publication2. The company first announced the results in press releases: the first trial in July 20255 and the second in August 20256.
Arash Mostaghimi, a dermatologist at Brigham and Women’s Hospital and Harvard Medical School, was quoted in AbbVie’s announcements praising the results56. ScienceAlert credits the published paper to Mostaghimi and colleagues2. Benjamin Ungar of Mount Sinai, who gave Healio an independent-style perspective calling the results “very impressive,” disclosed financial relationships with AbbVie and many other drugmakers5.
How it fits the field
Rinvoq would not be the first pill of its kind for this condition. Three other JAK inhibitor pills are already approved by the US Food and Drug Administration (FDA) for severe alopecia areata: Olumiant (baricitinib), Litfulo (ritlecitinib) and Leqselvi (deuruxolitinib)7. Rinvoq itself is already FDA-approved for rheumatoid arthritis, eczema, ulcerative colitis, Crohn’s disease, psoriatic arthritis and other immune conditions7.
Regulators have started to act on the alopecia data. In June 2026, a European Medicines Agency committee recommended approval for adults and teens with severe alopecia areata4, and the European Commission approved it in July 2026 for people 12 and older7. In the US, the drug is under FDA review for this use73.
Other approaches are also being tested. Biohack recently reported on an experimental injection for alopecia areata that works through a different route.
What to watch next
- The FDA decision on whether to approve Rinvoq for severe alopecia areata in the US7.
- Longer results. The program continues past 24 weeks: people on the drug kept taking it for another 28 weeks, and those who finish can join a third study lasting up to 108 more weeks4. These data should show whether regrowth holds and whether new side effects appear.
- Comparisons with existing treatments, which ScienceAlert notes are still needed to confirm how upadacitinib stacks up against the pills already approved, not just against a dummy pill2.
Biohack will follow this thread as regulators and researchers report new results.
