Baldness will develop in susceptible individuals because of the actions of a hormone, dihydrotestosterone (DHT), on the hair follicle, which causes it to become inactive. When a follicle becomes inactive the hair will fall out but the follicle itself never dies, it just lies dormant for an indefinite period of time.
In the male, testosterone is converted to DHT through the action of an enzyme called 5 alpha-reductase. Some men are born without this enzyme and it has been noted that they do not develop hair loss, acne, or an enlarged prostate.
Scientists have documented higher tissue levels of DHT in the bald scalp as compared to the hairy scalp. It was then surmised that if DHT levels could be reduced, then baldness would be slowed down or even reversed.
For a more detailed review of baldness and its treatment, please see Dr. David O'Brien's excellent article, “Hair Restoration Surgery: A Brief Overview of its History and Current State of the Art.”
Finasteride: a 5 alpha-reductase inhibitor.
Finasteride (Proscar® or Propecia®) inhibits the conversion of testosterone to dihydrotestosterone. Proscar® is only available as a 5-milligram pill and has been used for years to improve urinary flow in men suffering from benign prostatic hypertrophy (BPH). Scientific studies have clearly documented that men taking finasteride have significantly reduced scalp levels of DHT. The next step was to see if balding could be moderated by reducing levels of dihydrotestosterone in the scalp.
The jury is in and finasteride has clearly been shown to have beneficial effects on male pattern baldness. The good news is that approximately 90 per cent of men taking finasteride will stop losing hair and about 50 percent of men will actually start re-growing hair! The bad news is that the drug seems to work primarily on hair in the back of the scalp, a region called the vertex.
In an early 1995 study assessing the total change in hair counts, patients taking finasteride for 12 months had a mean increase of 95 hairs in a one-inch diameter circle drawn on the vertex of the scalp. This is compared to a mean decrease of ten hairs per one-inch diameter circle in patients taking a placebo (inactive pill).
Interestingly, the 1-milligram dose of the drug seems to work just as well as the 5-milligram dose with very few significant side effects. The main side effect is a reduced sex drive which occurs in a very small percentage of men taking finasteride.
Finasteride, as Propecia®, has been approved by the Food and Drug Administration for the treatment of male pattern baldness. Propecia® is available by prescription as a 1-milligram pill for oral administration only.
Finasteride use is contraindicated in women! The hormonal activities of this drug could cause abnormalities in the external genitalia of a male fetus if a pregnant woman receives finasteride.
There are now more options than ever for the medical treatment of hair loss. Of course, you need to see your personal physician before starting any treatment. Do not mistake the educational intent of this article as my personal recommendation to start medication for hair loss. The following statements, however, have a strong basis in scientific fact and theory.
Finasteride is clearly a very effective treatment for delaying the progression of hair loss, especially when started in the early stages of hair loss. Since 90% of men seem to stop losing hair when they take finasteride, it makes sense to start the drug as early in the balding process as possible.
Finasteride is also the best drug currently available for re-growing hair that has already been lost. Most studies to date have shown that the drug is fairly effective at re-growing hair that has been lost in the back of the scalp and is much less effective at re-growing hair lost from the front of the scalp. This is why many men use a combination approach of hair transplantation for the front of the scalp and medical treatment for the back of the scalp.
Used alone, this drug is more effective than minoxidil (Rogaine®) applied topically. There is some evidence that combination therapy using oral finasteride with topical minoxidil may yield even better results. Rogaine® is currently available over-the-counter as a 2 per cent solution. A more potent 5 percent solution is available by prescription only and, theoretically, may work better than the 2 percent solution when used in combination with the finasteride. One study used a solution of minoxidil and Retin-A® mixed together.
Studies have shown that the inactive hair follicle becomes clogged with an oily substance called sebum. It has been theorized that removal of the sebum will help reactivate the hair follicle. The Retin-A® is somewhat expensive, but apparently helps to unblock the sebum-clogged hair follicle.
For significant frontal hair loss the best cosmetic option remains hair replacement surgery in which hair from non-baldness prone areas of the scalp are transplanted to the frontal region. These hairs are then permanent residents in their new home. In recent years there have been substantial technical advances in hair transplant surgery. In Jacksonville, we have high quality surgeons such as Dr. David O'Brien at the Mandarin Hair Transplant Center (# 886-9665) who uses modern techniques to achieve a natural frontal hairline.
One thing is certain; no matter what drug therapy you use for the treatment of hair loss…the treatment must be used forever. If the treatment is discontinued the hair loss will resume and any hair you have re-grown will be lost.