But surgeons can't make more hair. They can only move existing hairs around. "Sometimes we try to put the hairs in at an angle because it may cover more that way," Moy says.
An unlimited supply of hair would make all the difference.
Coaxing cell growth
In 1999, Colin Jahoda of Durham University in England made scientific headlines when he transplanted key cells from the follicle known as dermal papilla (DP) cells from his head to his wife's arm.
Soon enough, four new hairs sprouted.
It was, to be sure, an impressive party trick. But Jahoda's real aim was to show, first, that transplanted hair follicles wouldn't be rejected by the body like a transplanted heart. And, second, that these DP cells, on their own, were able to command the skin into which they were transplanted to grow an entire new follicle.
DP cells, just like hair, are in short supply on the scalp. But the dream is to remove a few hairs from someone's head, tease out the DP cells, let them multiply many times in a dish in the lab, then inject them back into the same person's bald spot, where they would cause many new hairs to grow.
Until recently, no one knew how to do that. Scientists could grow DP cells in a lab, but the cells lost their ability to induce new hair growth.
The key was "to find the 11 secret herbs and spices to let the cells multiply while still keeping the ability to grow hair," says Dr. Ken Washenik, executive vice president of Aderans Research Institute (ARI), based in Atlanta and Philadelphia.
Now two companies say they have done it: ARI and Intercytex, a biotechnology firm based in Manchester, England. These days, says Nick Higgins, chief executive of Intercytex, scientists can multiply the number of cells about a thousandfold.
ARI has been testing the cells in petri dishes using donated human skin left over from cosmetic surgery. It has shown that the cultured DP cells will grow nice, dark, pigmented hair, the kind you normally think of on the top of the scalp.
"We're growing human hair, and we're growing it on human skin," Washenik says proudly.
Intercytex, meanwhile, has started testing its cells on human heads. Last year, it conducted a clinical trial mostly to ensure the procedure was safe.
First, hair follicles were taken from the backs of the heads of seven balding men. Then the DP cells were dissected and grown in the lab in dishes.
Intercytex then went back to the same men and injected each man's DP cells back into his bald spot, just below the surface of the skin. It did about 100 injections per person in a half-inch-square area. "In five out of seven we got increased hair growth," Higgins says.
The long search for baldness cures may be drawing to a close, but for now, myths about hair loss still abound. People are still rubbing herbs and chemicals into their bald heads, hoping that something will work.
They're not using dog urine anymore. But today special shampoos with herbs and vitamins probably are about as useful.
Or \o7less \f7useful.
Urine, pigeon droppings and other skin irritants can cause transient hair growth, in the same way that hair tends to grow underneath a plaster cast.
Even being licked by a cow might be beneficial. Cow saliva contains epidermal growth factor, which can stimulate cells in the follicle to make hair more quickly.
As surgeons start to mass-produce hairs in dishes and dermatologists scribble out prescriptions for potent, hair-growing salves, the era of folk remedies -- of laser combs, oil of wormwood and herbal shampoos -- may finally end.
No one will need cow saliva anymore, except the cow.
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Did you know that...
* The longest hair on record belongs to Xie Qiuping of China, according to the Guinness Book of World Records. It measured 18 feet, 5.54 inches on May 8, 2004.
* Hair typically grows at about 0.5 inches a month, making it the second fastest growing tissue in the body after bone marrow.
* At any one time, 90% of scalp hairs are actively growing, while 10% are resting.
* People normally lose around 100 hairs a day.
* Cutting hair does not change its growth rate.
* The average scalp has 100,000 hairs. Blonds typically have the most hairs, while redheads have the fewest.
* Everyone is born with as many hair follicles as they will ever have. Follicles may change the type of hair they produce, but their number doesn't typically change.
* Hair varies in thickness from about 1.5 to 5 thousandths of an inch, or from about half to twice as thick as a piece of paper.
* Hair is about as strong as a copper wire of the same thickness.
* Body hair and pubic hair stay shorter than head hair because the growth phase of hairs in these regions is much briefer.
* Hair follicles usually cycle through growth and shedding randomly, so that you're never losing large amounts of hair all at once.
* Sometimes follicles synchronize, releasing their hairs all at the same time, a condition called "telogen effluvium." This is what happens when cats and dogs shed in the springtime.