Follicles of the Future
Most men who lose their hair have a hereditary condition called androgenic alopecia, says Neil Sadick, M.D., Clinical Associate Professor in the Department of Dermatology at Cornell University Medical College. These men have increased levels of a hormone known as 5(alpha)-reductase, which changes testosterone to dihydrotestosterone (DHT). The DHT in turn causes follicles to sprout shorter and finer hairs before eventually dying out. It also causes the growth phases of hair follicles to become shorter, and the rest phases to be longer.
But researchers are discovering that this rest phase can be shortened. The October 1999 Journal of Clinical Investigation reported that scientists at the Weil Medical College of Cornell University succeeded in nudging hair follicles out of their rest phases -- at least in mice. They used an altered form of cold virus to deliver what they have named the "Sonic hedgehog" gene (after a video-game character), which plays a central role in hair follicle development. This therapy spurred the mice to sprout new hairs, presumably by causing those in the rest phase to enter the growth phase. Researchers say further study is needed before it is known if this therapy could potentially help those with male pattern baldness.
Lend Me Your Hair
Another potential treatment for balding was described in the November 1999 issue of Nature. Researchers found it was possible to grow hair follicles and hair from donated follicle cells.
Hair follicles are one of the few immunoprivileged parts of the body -- that is, they are protected from the immune system so the body doesn't treat them as foreign and attack them. Researchers thus wondered if they might be transplanted from one person to another without triggering an immune response and therefore rejection. Hair follicle cells, donated from the arm of a male scientist, were implanted into the arm of a female scientist. A few weeks later, she grew large, thick, dark hairs -- unlike her own -- in the area of the transplant.
In what is currently a standard hair transplant, follicles are transplanted from one part of the patient's scalp where hair is present, to another where hair is sparse. In other words, more hair is not being created, but just spread around. The amount of coverage that can be obtained depends on how many active hair follicles still remain.
If the cell-transplant approach were to develop into a viable technique, it would actually create new hair follicles and have distinct advantages over current methods. "There's no limitation to the number of new hair follicles," says Peter B. Cserhalmi-Friedman, M.D., one of the study's authors and an associate research scientist in the department of dermatology at the College of Physicians and Surgeons at New York City's Columbia University. "Because you don't have to remove a follicle from someplace else, it can probably be used not only on people with good hair on one part of their scalp but also on people without any hair."
But don't start looking for an ideal donor yet. Any new techniques in this area would probably not be available for at least another decade, says Sadick.
Fortunately for those who still have hair on their heads, there's something you can do in the here and now. But time is of the essence, says Sadick, since the two FDA-approved drugs for hair growth work better when the hair follicles are not yet dead, when they still have some activity and can be saved.
Finasteride, sold under the brand name Propecia, is taken as a daily pill. A September 1999 New England Journal of Medicine article that reviewed the literature on hair loss found that after two years of treatment, two-thirds of the men taking this medication had improved scalp coverage, with higher hair counts and longer, thicker hair. A very small number of men experienced a decreased libido with the drug, but these side effects usually disappeared during prolonged treatment.
For those who don't want to take a pill, minoxidil (sold under the brand name Rogaine) is a treatment that must be applied twice daily to the scalp indefinitely. However, it works for fewer men than finasteride does, says Sadick. The main side effect is skin irritation.
Since few insurance plans cover either drug -- or the surgery, for that matter -- and you need to take them without interruption to get the benefits and maintain them, hair-transplant surgery is probably more cost-effective, says Sadick.