Scientists have completely reversed hair loss in three people by giving them a drug normally used to treat bone marrow disorders.
The patients had alopecia areata – a condition that can cause severe, patchy baldness that is difficult to treat.
But after five months of taking the medication ruxolitinib, all three saw total hair re-growth.
The findings from Columbia University Medical Center are published in the journal Nature Medicine.
Alopecia areata affects around two in every 1,000 people in the UK and is thought to be caused by the immune system attacking hair follicles.
The US scientists had previously identified a set of immune cells involved in the destruction of hair and conducted a number of successful trials in mice.
They then gave three patients with moderate to severe alopecia areata a twice daily dose of ruxolitinib.
This medication is already approved for use in bone marrow conditions in the United States and European Union.
All three patients had lost at least a third of their hair but saw dramatic hair growth within five months of therapy.
