Blocking DHT & Preventing Hereditary Hair Loss
Hereditary hair loss (also called male pattern baldness, female pattern baldness, and androgenetic alopecia, AGA) affects both men and women. It affects about 80 million men and women in the United States There are hundreds of treatments. More accurately, there are hundreds of claims of treatments. The vast majority of these don’t work. In a previous blog, I discussed the mechanism of AGA. In summary, testosterone, which is present in the blood stream of both men and women, is taken up by receptors of genetically programmed hair follicles in the scalp. In the hair follicle, it is converted to dihidrotestosterone (DHT) by an enzyme, 5-alpha reductase. DHT sends a chemical signal to the hair follicles to slow their growth. The affected follicles shrink, progressively producing shorter and finer hairs. Over time, the follicle is destroyed.
Currently, the key to treatment of AGA is to either, block formation of DHT, or stimulate the growth rate of the hairs. Blocking DHT is accomplished through the use of agents, which block 5-alpha reductase. Finasteride (PropeciaR) is the most common of these agents. Taken as a once-a-day prescription pill, it is FDA-approved to treat AGA in men. It is approximately 80-90% effective. Minoxidil (RogaineR) is thought to prolong the growth phase of the hair. It is approximately 80% effective. It is applied directly to the scalp daily. It is available without prescription. 5% Minoxidil is approved for use by both men and women. As both these agents are blocking a naturally occurring, genetically based process, they must be used indefinitely. They are not a cure. They are meant to “freeze-frame” the hair. They hold back the forces of Mother Nature. They do not create new hair follicles. However, with these two treatments, many of the hairs, which have become miniaturized, may return to full normal size. Thus, it may seem as if there are new, thicker hairs. Finasteride (for men) does this better than minoxidil. Merck, the creator of Propecia, , did a study showing that the weight of the hairs actually increases with treatment. This effect maxes out within about two years of starting treatment.
There are a number of secondary treatments which block production of testosterone. These are called antiandrogens. Spironolactone is an example of an antiandrogen. It is less effective than finasteride and minoxidil.
Another interesting agent is topically applied progesterone. Progesterone, a naturally occurring hormone in females, blocks 5-alpha reductase. Thus its mechanism is the same as finasteride. It can be used in men and women safely. It is a treatment I have offered in my practice for many years.
If you have AGA, my advice is to commit yourself to the regular use of these products. You must be convinced that, without treatment, your hair is going south. It is waste of time and money to start, then quit. Some people start treatment because they are alarmed at the progressive thinning and recession of their hair. Over time, however, they may become discouraged, noticing no change in their hair. Well, that’s a good thing. Not losing more hair is the point. But it can be boring to watch nothing happen. However, one way to think of these treatments, is that they will keep you in the game (hold on to your hair) until a newer, better treatment comes along.