Originally developed as a treatment for prostate gland enlargement, Finasteride is a drug that is now also used for the treatment of male pattern baldness (male hair loss).

During the 1980s and early 1990s large amounts of time and money were spent on research trying to find a cure for enlarged prostate gland in men. The condition was and still is very common, it affects about half of all men in their 60s and possibly 95 per cent of all men by the age of 80. As a man gets older the condition progressively worsens as the prostate enlarges putting increased pressure on the bladder. Early symptoms may show up as a difficulty maintaining urine flow and the need to urinate frequently. This progresses to more painful and serious conditions such as infections of the urinary tract and the development of bladder stones.

By 1993 medical researchers had found that the condition was caused by a hormone called dihydrotestosterone (DHT). It then became clear why the condition was only found in men, as DHT is created from the male hormone testosterone by the enzyme 5-alpha-reductase (As a side note, DHTs’ only known positive role is to enlarge the male genitalia during development of the foetus). Once the mechanism of how and why the prostate was being affected a drug called Finasteride was developed that prevented an enzyme called 5-alpha-reductase from converting testosterone into the damaging DHT.

The drug was extremely successful at treating prostate gland enlargement and soon became used on a large scale. This was when the amazing Finasteride side effect was discovered, for it was observed that Finasteride was actually preventing male pattern hair loss in the patients being treated. This was a remarkable breakthrough, backed up with compelling statistical evidence.

It is now generally accepted that DHT causes hair loss, although the actual mechanism that causes the condition is still unclear. One theory is that DHT interrupts the hairs normal growth cycle by shortening the growing phase (Anagen) of the hair and lengthening the resting phase (Telogen).

Once the link between DHT and hair loss was established it opened the floodgates with companies trying to produce the most effective form of anti-baldness drug. Research soon found that a much lower dosage of the drug, about one fifth of that required for treating prostate gland enlargement was required to stop hair loss. This was good news for creating a safer drug but there are still a number of side effects that should be considered before use. These side effects include erectile dysfunction, loss of libido and gynecomastia i.e. the enlargement of the breasts in men. The manufacturers claim that these side effects will affect less than 2% of users.

In December 1997 Finasteride was approved as safe for use in treating male pattern baldness by the American Food and Drugs Administration (FDA). Finasteride is now probably the most a very effective drug for preventing hair loss in men but should be taken with caution as the possible side effects can be long lasting. Some doctors can also prescribe Finasteride for women but it should never be used by pregnant women or women who may become pregnant as its side effects can cause defects in the unborn foetus.