Hair Growth Cycle

In Various parts of the human body, the hair follicle being one of them, exists an enzyme called 5-Alpha-Reductase, or 5AR. This enzyme reacts with the male hormone testosterone to synthesize a new male hormone. This derivative of testosterone is called Dehydro-Testosterone, or DHT (picture 1).

Picture 1: 5-A-R Synthesizes Testosterone to Dehydro-Testosterone

When Dehydro-Testosterone binds to hormonal receptor sites, on follicles located on the mid and frontal parts of the scalp (pictures 2 & 3), it causes an auto immune reaction that damages the follicles. The body's immune system falsely recognizes the follicles to which the Dehydro-Testosterone is bound as foreign intruders, and attacks them until they are eventually destroyed.
During the adolescence years testosterone levels are relatively low, and are insufficient to cause any harm to the hair follicles. After that period there is a substantial rise in body testosterone and Dehydro-Testosterone levels, which starts affecting the hair follicles. They gradually shrink, their growth phase shortens and resting phase lengthens. The hair they Produce is thinner and of lesser quality. This process continues until they are

completely dysfunctional (pictures 4-6). Another effect attributed to Dehydro-Testosterone, is the damage inflicted upon blood vessels in close vicinity to the scalp. The impaired vessels deliver fewer quantities of the elements required for the production of Keratin and Melanin, an effect that might contribute to hair loss. Even if there is truth behind such an assumption, it could not cause baldness by itself.
		Picture 2		Picture 3

Dehydro-Testosterone is the main cause for Hair Loss and Male Pattern Baldness , or in its scientific term Androgenetic Alopecia. This is the form of hair loss which most balding men suffer from. Thanks to medicine we now have the ability to cope with the destructive effects of Dehydro-Testosterone, but this ability is not unlimited, and its effectiveness is largely dependant on the stage at which treatment begins.

Dehydro-Testosterone is only harmful when it binds to hormonal receptor sites on the hair follicles. The number of sites on each follicle varies in different individuals and that is why some of us suffer from hair loss and go bald and some don't.

	Picture 4		Picture 5		Picture 6