On the surface, you might very reasonably wonder what the prostate gland and hair have in common. The link is the hormone dihydrotestosterone (DHT), which is formed in the body from testosterone, the male hormone. DHT plays a critical role in the growth of the prostate gland and in causing male-pattern baldness—both problems of concern to aging males.
The drug finasteride blocks the enzyme responsible for the formation of DHT. Merck markets this same drug, taken only by men, as Proscar (1992) when used for prostate problems and as Propecia (1996), at a lower dose, for male-pattern baldness.
First, a little background: At the climax of male sexual stimulation, the ejaculate contains the prostate gland secretion that increases sperm movement and promotes egg fertilization by neutralizing fluids in the vagina. In young men, the prostate is walnut-size, but after age fifty, it begins to grow. This noncancerous enlargement is called benign prostatic hypertrophy, or BPH. As BPH progresses, it compresses the urethra—the tube draining urine from the bladder and out the body—decreasing how much can be urinated on each occasion and greatly increasing how often the urge to urinate occurs.
When taken over a six-month period, Proscar gradually shrinks the prostate gland and improves the symptoms of BPH, including increased urine flow. The drug also serves as a safer alternative to BPH surgery. However, Proscar’s ability to prevent prostate cancer remains unclear.
High levels of DHT also cause hair follicles to shrink, leading to male-pattern baldness, which affects almost half of men by age fifty. Propecia restores hair growth and prevents further loss, primarily on the crown of the head. Have no fear: the hair will not grow to cover the eyes. The effects of Propecia are modest, with only about half the men showing what consumers would generally consider to be reasonable hair growth.
Both Proscar and Propecia must be taken indefinitely. Once their use is discontinued, the prostate resumes increasing in size and hair is, once again, lost.
SEE ALSO Testosterone (1935), Rogaine (1988) Flomax (1997).
Balding by the age of 23, Louis XIII (1601–1643) popularized wigs in the French court—a fashion that soon swept throughout Europe and remained in vogue for almost 200 years. Wigs were worn by women and men and viewed as symbols of wealth and status.