The US Food and Drug Administration (FDA) has approved a pill for severe hair loss.
Approval of the drug baricitinib will "help fill a significant unmet need for patients with severe alopecia areata," FDA director of dermatology Kendall Marcus said Monday.
Baricitinib regulates inflammatory reactions and has so far been approved for the treatment of arthritis and corona patients in hospitals.
Alopecia is an autoimmune disease that causes excessive hair loss.
The disease was recently brought to the fore by the case of US actress Jada Pinkett Smith.
Her husband Will Smith slapped comedian Chris Rock at the Oscars for a joke about his wife's bald head.
The disease is not uncommon;
in the US alone, more than 300,000 people are affected each year.
The drug's approval is based on the results of two clinical studies involving a total of 1,200 adults with severe alopecia.
In each study, participants were divided into three groups: one group that received only placebo, a second group that received a two-milligram daily dose, and a third group that received a four-milligram daily dose.
After 36 weeks, almost 40 percent of the people who received the higher dose had regrown 80 percent of their scalp hair.
For comparison: in the group with the lower dosage it was only 23 percent, in the control group only five percent.
The most common side effects of baricitinib included upper respiratory tract infections, headaches, acne, high cholesterol, and increases in an enzyme called creatine phosphokinase.
There are other treatments for severe hair loss, but they are considered experimental and not approved in the United States.