Now doctors say a big breakthrough could make that possible.
While studying the cells of men undergoing hair transplants Dr. George Costarelis says he and his team made a surprising discovery.
"The scalp that's bald still has the same number of stem cells as the scalp that's not bald," Dr. Costarelis says.
The problem is, even though the stem cells exist they aren't producing a different kind of cell called a progenator cell.
"These are the ones that are the work horse cells. They are constantly making the hair," Dr. Costarelis explains.
He says he is hopeful researchers will find a way to turn the inactive cells back on.
"We know the stem cells are present. They're not gone. If they gone it would be more difficult to design a treatment. But current treatments are very good at maintaining the hair you have. This one would be geared towards actually reversing hair loss. So even if you're bald, theoretically this would be able to activate the stem cells and get new hair to grow in," he says.
Doctors don't know if baldness in women works the same way.
"Many of my patients are women, most of them actually are women and I would really like to be able to help them more than what I can currently. So in the future I want to figure out if these same principles apply to female pattern hair loss," Dr. Costarelis says.