A pill that appears to cure alopecia has fully restored the hair of three patients in a breakthrough hailed by scientists as "dramatic" and "exciting".
Doctors conducted a pilot trial after identifying which immune cells were responsible for destroying hair follicles in people with the condition.
Within four or five months of being put on the drug, ruxolitinib, all three patients experienced complete hair regrowth.
"We've only just begun testing the drug in patients, but if the drug continues to be successful and safe, it will have a dramatic positive impact on the lives of people with this disease," said Dr Raphael Clynes, from Columbia University Medical Center in New York.
However, the team said further tests were needed before the drug can safely be used as a baldness treatment.