Male pattern baldness is by far the most common type of hair loss and affects the majority of men to varying degrees. Traditionally, it has been held that male pattern baldness can be traced to one’s mother’s father but this perspective is highly simplified and distorted. In fact, there are many genes for hair loss and the inheritance pattern is complex and derives from both sides of the family.
Unfortunately, hair loss is progressive in nature. The earlier and more rapid the onset of hair loss in a man, the greater likelihood that this hair loss will progress toward extensive hair loss in the not so distant future. Fortunately, today there are medical solutions to manage male pattern baldness, which if started earlier can afford better results. The Internet is filled with hawkers of miracle cures, but there are only two FDA-approved products, finasteride (marketed as Propecia) and minoxidil (marketed as Rogaine) that have proven efficacy.
First, we must understand how we lose hair in order to understand how these products work effectively to combat hair loss. Male pattern baldness involves the slow but progressive transformation from thick, terminal hairs of youth to baby, short, wispy vellus hairs, and then finally to complete absence of hair. When 50% of hair is lost, noticeable thinning begins to be apparent. Finasteride and minoxidil both work toward returning vellus hairs back toward thicker, terminal hairs but they cannot work in the absence of discernible hair, i.e., so-called “slick baldness.”
Accordingly, the earlier in the process of hair loss that these medications are started, the more effective they will be to help slow down and reverse to a certain extent the existing hair loss. If started late in the process of hair loss, they are less effective in managing/reversing the hair loss condition.
The mechanism by which minoxidil works is not entirely clear but it is thought to act as a cellular proliferator or to keep hairs in their growth phase (known as anagen) for a longer period of time. Minoxidil, which is over the counter now, is a topical preparation meant to be applied to the scalp twice daily. Anecdotally, it is thought that the half life of minoxidil in the scalp may be close to 20 hours, meaning that even once a day application can be substantially better than not at all. The package insert reads that minoxidil is only indicated for the crown/vertex region. However, this information is outdated and reflects only the original FDA studies performed over a decade ago. Although new FDA trials were not financed, subsequent studies have shown almost the same benefit in all regions of the scalp.
Minoxidil can lead to temporary increased shedding 3 to 4 weeks after starting the product and that must be known in advance to limit fear on the patient’s part. This temporary effluvium correlates with hairs cycling into the growth or anagen phase, which is a good indicator. In addition over 20% of individuals can experience a delayed (less than 72 hours) or immediate allergic skin reaction to minoxidil, which is significantly more common with the generic or brand named liquid version. The foam version that only comes as brand name Rogaine and only in the 5% male strength has virtually eliminated this problem by removing the propylene glycol component. Minoxidil typically starts to show effect rather quickly within 6 weeks to 3 months. As a reminder, hair loss will continue to occur. Minoxidil will simply slow down the hair loss as well as rethicken some miniaturized vellus hairs.
Finasteride, an oral pill taken once daily at a 1 mg dosage, is prescription only and helps to slow down and reverse some vellus hairs. It is a medication that takes typically 4 to 6 months to start showing benefit and unlike minoxidil is only indicated for men, as it can cause birth defects in women of childbearing age who take it and has shown little benefit in women who are postmenopausal. Of note, there is no negative effect on children for men who take the medication and impregnate a woman. Finasteride is a dihydrotestosterone (DHT) blocker, that inhibits the conversion of testosterone to DHT via the pathway of the 5-alpha reductase enzyme. The presence of DHT in the scalp causes hairs that are sensitized to possible loss of hair to lose that hair. Because DHT receptors are partly located within the blood vessels that reach the hair follicle, topical finasteride has not shown to be of commensurate benefit as oral medication.
The major side effect with finasteride is sexual, including erectile dysfunction, loss of libido, and possible breast tenderness and/or growth. The incidence of this side effect profile is 1% when compared against placebo and only shows statistical significance when all side effects are aggregated. Side effects are reversible with cessation of the medication, and 57% of men who continue to take the medication show a resolution of their side effects. The individual who takes finasteride should also know that the prostate specific antigen (PSA) value is reduced by half and should therefore be doubled during calculation for men who are being screened for prostate cancer. In addition, because finasteride is metabolized by the liver, liver function tests should be undertaken before starting the medicine and should be followed by a physician as directed. The most recent study in 2008 showed that there is a potential 25% reduction in long-term prostate cancer risk for those who take finasteride.
Finasteride and minoxidil work synergistically to combat hair loss even better than if they were taken in isolation. Those who are willing to take both products and who have been guided by a physician for proper understanding of the risks, benefits, and limitations, should consider doing so. However, one major limitation with both products is that if one should in the future decide to stop taking either product, all the hair that was gained or maintained by that product will be quickly lost over a period of several months. This limitation should always be clearly understood.
Understanding the medical nature of hair loss in men is a prerequisite step before entertaining the desire for possible hair restoration surgery.