DHT and Hair Loss

DHT or Dihydrotestosterone is a male sex hormone, or androgen, derived from testosterone, and probably responsible for over 90% of hair loss, especially in men. DHT is formed mainly in the prostate gland, testes, hair follicles, and adrenal glands, by the action of the enzyme 5a-reductase, and acts to develop and promote masculine characteristics.

DHT is a powerful sex hormone that can adversely affect both the prostate and hair follicles on the head. The mechanism is not fully understood, but it seems that it affects some people more than others depending on their genetic predisposition. On the head DHT initiates a process of follicular miniaturization or shrinkage, so that the hairs produced become thinner and more fragile. Eventually one is left with a “peach fuzz” appearance before the follicles finally cease to produce any hair at all.

It may be that DHT acts on the dermal papilla to prevent sufficient proteins, vitamins, and minerals from being adequately absorbed from the blood stream and reducing the supply of nourishment to the follicle.

Gradual loss of hair leads of course, to the development of baldness, and in men it tends to follow a common pattern in that the hairline recedes gradually, often followed by the appearance of a bald patch on the top of the head. As loss of hair continues the bald areas coalesce, leaving a typical appearance of a horse-shoe shaped area of hair remaining. In women, hair loss tends to be more widespread and diffuse, and it is now thought that this may be caused by testosterone rather than the more powerful dihydrotestosterone.

Exactly how male pattern baldness has evolved is difficult to say, but one theory is that baldness has developed in males through sexual selection as an enhanced signal of aging and maturity, coupled with an appearance that is less aggressive and more nurturing. This theory, though, seems rather far-fetched to many.

Several available treatments for baldness attempt to counter the effects of DHT by either inhibiting its production, or by interfering with its action on hair follicles. One commonly used anti-androgen is finasteride, which inhibits the conversion of testosterone to DHT by interfering with the enzyme 5-alpha-reductase.

Finasteride is usually taken by mouth as one tablet per day, and is reckoned to slow hair loss in 85% of men who take it. Some growth of new hair has been seen in about 65% of cases. As hair grows only slowly (about 1 inch every two months), it can take some time before improvements are noticed. Possible side effects such as impotence occasionally occur. Finasteride is usually prescribed only for men as it has been claimed to produce birth defects in male foetuses. Finasteride has gained approval by the FDA and is generally accepted as improving the appearance of baldness in most people, although it seems to work better in restoring hair to the crown of the head rather than at the front.

There are some naturally occurring DHT blockers, of which the best known is probably saw palmetto. This lowers levels of DHT in the body by blocking 5-alpha-reductase, and also appears to block receptor sites on cell membranes required for cells to absorb DHT Studies have shown saw palmetto to be a potent DHT blocker without any serious side effects, although these have mainly been carried out in the area of benign prostatic hyperplasia, a condition also attributable to excess DHT.

Other natural substances which help block DHT are: Pygeum extract, pumpkin seed oil, green tea, emu oil, soy isoflavones, and Beta Sitosterols.

Additionally, it has been claimed that using L-Lysine in conjunction with DHT blockers, can make a more effective combination.

Anyone suffering from male pattern baldness and seeking relief, would be well advised to see their doctor for advice on whether a DHT blocking drug or natural derivative might be appropriate.