Johns Hopkins Focus: Preventing Baldness with Drugs

By S. Elizabeth Whitmore, M.D.

The two FDA-reviewed and –approved options for treatment of male-pattern baldness are finasteride and minoxidil.

Debunking Hair Myths

Wearing a hat contributes to baldness. Wearing a hat outdoors may actually be good for men, because sunlight hitting the scalp may promote hair shedding.

Dietary factors. Rapid weight loss can contribute to temporary hair shedding, but not baldness.

If Dad went bald at 35, I'll do the same. You may go bald sooner, later or not at all. Having a genetic predisposition doesn't mean the baldness will manifest itself in the same way it did in others in your family.

Baldness skips a generation. Sorry, but every other generation doesn't necessarily get a break.

Too much shampooing or stress can cause baldness. Neither is related to patterned baldness.

In the not-too-distant past, the only recourse for the 40 million American men with male pattern baldness was to live with it, buy a toupee or undergo surgical hair transplantation. Now, there are two options for some men (one is also an option for women) to regrow lost hair or minimize further hair loss.

The latest and most convenient treatment is finasteride (Propecia), the first baldness treatment that comes in pill form. Since the mid-1980s, a liquid solution minoxidil (originally sold by prescription as Rogaine but now available non-prescription in generic form) could be applied to the scalp twice a day in an effort to regrow hair caused by male-pattern baldness; called "androgenetic alopecia."

Propecia received FDA approval in December 1997 and was introduced in early 1998 after numerous multi-center trials in the United States and Europe, including here at Hopkins. Although the studies looked at different outcome factors and therefore results cannot be compared directly, it appears as though Propecia produces similar results as the 5 percent solution of minoxidil, known as Extra Strength Rogaine. It typically increased hair amount in about half the men who used it for one year and in two of three men who used it for two years. Hair amount increased by about 15 percent in these men.

Women who experience hair loss must stick with minoxidil, since finasteride has been approved only for men.
In fact, women who are or may become pregnant shouldn't even touch broken or crushed tablets, because finasteride can cause abnormalities in the sex organs of male fetuses.

In both sexes, androgenetic alopecia is caused by a combination of two factors: an inherited predisposition toward baldness — from either side of the family tree; and stimulation of those hair follicles that are sensitive to the male hormone dihydrotestosterone, or DHT. An enzyme, 5-alpha reductase, converts the male hormone testosterone into the more potent DHT at the hair follicle.

This causes hair loss and eventually, prevents new hair growth. Propecia works by inhibiting the 5-alpha reductase enzyme so it prevents the conversion of testosterone into DHT. Rogaine, on the other hand, is thought to directly stimulate hair growth totally independent of any hormone effect.

Neither Propecia nor Rogaine will grow a thick mane. Initial growth will be very fine, like peach fuzz. If hair growth continues, these new hairs will take on the color and texture of the rest of your hair. Both medications work on the top of the scalp and crown, and will not add hair to a receding front hairline. They are effective only during the thinning process; they generally don't work on people with hairless or nearly hairless scalps.

Which is better? Both have advantages and disadvantages.

Finasteride

Originally used at a higher dose to treat prostate enlargement under the name Proscar, finasteride is not yet available in generic form. Its main advantage is convenience. Taking one pill daily can produce hair growth starting in about three months.

In test trials, about 2 percent of men experienced impotence. This drug is also expensive, costing about $50 a month, and must be used even after new hair is grown to maintain that new growth. Because it is a new drug, there may be other side effects that have not been documented. And it is not approved for women, no matter their age.

Minoxidil

First marketed as Rogaine (2 percent) and now sold under a host of generic names (such as Xandrox), minoxidil was the "original" baldness treatment, coming to the market in 1988. It is now sold over-the-counter. Users must rub the liquid on their heads twice a day, and if results are seen, it is usually within 6 months. A 2-ounce bottle of Extra Strength Rogaine (5 percent), which lasts about a month, costs about $30; it, too, has only been approved for men and can be expected to produce more hair more rapidly than the 2 percent Rogaine — 45 percent more, starting within 2 months.

We're not exactly sure how minoxidil works. It was initially believed that, because the drug was developed as an anti-hypertension agent and it dilates or opens blood vessels, it promotes hair growth indirectly by increasing the blood supply, thereby increasing nutrients delivered to hair follicles. Now it is thought to directly stimulate hairs of the follicles, which cause hair growth. This effect is totally independent of any hormonal change.

Because minoxidil is applied topically, there's less risk of side effects typically associated with medications that are taken orally. Also, minoxidil has been on the market long enough to spawn cheaper, generic versions. But it can be messy and time-consuming to use and can grow hair on areas where it has been repeatedly splashed. Another disadvantage: Some men find that minoxidil creates a powdery dusting on the head, while others infrequently experience an irritant or allergic dermatitis.

It is important for people who choose either product to realize that the main goal of treatment is to maintain hair. This, however, can be very significant, as studies over 5 years have demonstrated. It's probably best to think of treatment as being analogous to antihypertensive medications for high blood pressure: The purpose of treatment is to prevent what might happen over many years in the absence of treatment.

S. Elizabeth Whitmore, M.D., is an associate professor of dermatology at the School of Medicine who participated in the Hopkins clinical trials of finasteride.

Last Updated: 10/4/2002
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