In the normal scalp, somewhere between 80 percent and 90 percent of hairs at any point in time are in an active growing phase called anagen during which scalp hairs grow approximately one-half inch per month in young individuals (somewhat more slowly in seniors). The remainder of hairs are in a resting stage, which typically lasts for two to three months, a period that eventuates in shedding known as telogen. A “full head of hair" normally contains about 100 thousand hairs (somewhat less for redheads and somewhat more for blondes), and sheds between 50 to 100 hairs every day. If you believe you are losing more than this per day, or that your hair seems to be thinning or the hairline receding in the front, temples or crown of your head, you may be suffering from androgenetic alopecia, otherwise known as hereditary pattern baldness.
Contrary to conventional wisdom, balding or male pattern hair loss (MPH) is not inherited from the father’s side of the family only, but from both sides, and an examination of family history should therefore look at the maternal and paternal family history carefully for a genetic predisposition. Moreover, women themselves can suffer from an analogous hair loss problem (although they rarely go completely bald), female androgenetic alopecia.
Fortunately, these days if you are experiencing hair loss, you needn’t collapse in despair and resign yourself to a lifelong sentence of toupees and hats. Right now a variety of drugs and therapeutic strategies are available through physicians and still others are actively being sought by investigators.
Since there are many other common causes for hair loss, the first step should of course be a trip to the dermatologist to rule out other possibilities or aggravating factors, which range from fungus infections, inflammatory conditions, alopecia areata, stress-induced hair loss, or resulting from certain medications being taking for other conditions.
Proper hair grooming and styling practices can help those with thinning hair make the most of what they have. For example, the regular use of moisturizing shampoos followed by conditioning rinses containing panthenol (eg. Carmol Shampoo, DHS Conditioning Rinse) can help to temporarily increase the apparent thickness of individual hairs, minimize friction, and decrease the likelihood of strand splitting or breakage due to brittleness. The daily ingestion of 1200 mcg per day of the vitamin biotin may also be helpful.
Within the past three years, Pharmacia & Upjohn introduced Rogaine Extra Strength, a 5 percent topical solution of minoxidil. This represented a 150 percent increase in potency over the company’s previous 2 percent formulation. Investigators are still not sure of the exact mechanism by which minoxidil works. However, speculations include directly stimulating hair growth or increasing the blood supply to the scalp.
Preliminary studies have indicated that the new high potency version significantly increases success rate. With the previous topical only about 38 percent of men could expect to see any hair growth. With the new formulation this figure is believed to exceed 50 percent. What is even more encouraging is that greater than 95 percent of patients can expect to stabilize (ie. hold on to what they still have), especially if treatment is begun early (and the earlier the better).
As with any therapy, there are downsides. Unfortunately, minoxidil is most effective for hair loss in the vertex area,( the crown of the head), and does little for frontal or temporal loss. In addition therapy is lifelong discontinuance will result in gradual loss of all benefits within several months. Occasionally, the solution may provoke irritation or contact allergy. And lastly, since it takes at least four months, and more commonly in my experience, between eight and twelve months to see a response, a patient must endure a relatively lengthy waiting period and expense before even knowing whether he will eve see results.
Increased response rates have been reported in preliminary work when minoxil is used in combination with topical tretinoin (Retin A), which by itself has occasionally been found to promote hair growth. Again the precise mechanism by which the tretinoin works for hair growth remains unknown. It possibly may increase circulation to the scalp, and may serve to alter the skin surface of the scalp to permit greater absorption of the minoxidil. In over fifteen years of use, I have found combining the two topical agents more effective than either used alone and routinely prescribe the combination.
Also within the past three years, Merck & Co. introduced finasteride, (Propecia) the first oral product ever approved for male-pattern baldness, and the first agent that works for frontal hair loss. A reduced dosage form of Proscar, which has been used for well over a decade in older men to treat benign prostatic enlargement, Propecia, which is taking once daily, is an inhibitor of 5-alpha reductase (the enzyme responsible for converting testosterone to dihydrotestosterone(DHT) in the prostate gland and the hair follicles). DHT within the hair follicle is believed to be the major hormone for promoting hair loss. Hair regrowth was seen in between 50 percent and 65 percent of those treated in initial studies.
For some men who have not responded to finasteride, switching to a related medication, dutasteride (Avodart, like Proscar used to treat an enlarged prostate) has been found useful for promoting hair growth in MPH.
While no clinical investigations in humans have directly examined the combined use of minoxidil and finasteride, this combination in animal models demonstrated an additive efficacy. For this reason, many physicians, myself included, frequently take a more aggressive approach and routinely offer combined topical and oral therapy in appropriate candidates. At the same time, we always try to temper expectations of massive regrowth by emphasizing the benefit of stabilization that is far more likely to occur with medical intervention.
But finasteride, too, has its downsides. Decreased libido and sexual function have each been reported in about 3 percent of patients of men. Fortunately, both these side effects clear within twenty-four hours of stopping therapy. Moreover, benefits typically take several months to up to a year to be fully realized, giving rise to the same problems noted with minoxidil of prolonged waiting and expense. And finally, therapy must be lifelong, since hair will once again gradually begin to be shed about four months after cessation of treatment.
Not everyone benefits from, nor is everyone a candidate for, our current therapies. Medical intervention is unlikely to be effective for those with extensive hair loss, especially if present for many years. For such individuals, if they have sufficient donor sites, hair transplant surgery may be a viable alternative. Today’s newer techniques and combinations of micro, mini and regular grafts have been yielding far more natural-looking pelage than ever-before possible. At the same time, intensive research continues into new topicals, such as topical finasteride solution, and newer more selective, more potent oral 5-alpha reductase blockers, including GI198745, FK-143, and Turosteride. The overall good news is that the juggernaut to save our hair is continuing full steam ahead. Why wait to lose more hair. Consult with your doctor now.
