Propecia

Manufacturer: Merck.

Propecia web site.

Active Ingredient: Finasteride. Dosage: 1mg/day.

Propecia is defined as a 5-Alpha-reductas enzyme inhibitor. It binds to the enzyme to prevent it from synthesizing testosterone to Dehydro-Testosterone (picture 1).

Best results are obtained after two years of use, but early results can be seen after only a few months. The success rates are very high: in double blinded studies it has been shown effective in stopping hair loss on 83% of the patients. On 65% it has achieved regrowth as well. According to Merck propecia is effective at the crown and mid scalp areas. There is no conclusive data on how Propecia affects the frontal hairline and temples, even though there is evidence showing that it is effective in these areas too.

Picture 1: Propecia binds to 5AR

Once a patient discontinues the use of Propecia, hair loss will resume and within a few months he will lose all the results he gained from using it. After that period, benefits from reusing Propecia will again require at least several months of use. That is why it is highly unrecommended to stop using Propecia even for a short while. Propecia is taken orally as a pill once a day and is for use of men only. Pregnant women or ones still planning to conceive should not use this drug, as It can cause severe defects in male fetuses. A study on post menopausal women has shown Propecia to be ineffective on females.

According to Merck, possible side effects that may occur as a result of the use of Propecia are a decrease in sexual drive, sperm count and the ability to achieve and maintain an erection. These side effects can easily be attributed to the lowered levels of DHT, as it is the most potent of the male hormones. These side effects appeared on 2% of the men in the trial group. Roughly the same amount has also been reported in the Placebo group (unknowingly receiving sugar pills instead of Propecia), further undermining the connection between Propecia and the side effects. All side effects should disappear once discontinuing the use of the drug.

Men using Propecia must not donate blood. DHT has a significant role in the development of male fetus genitalia. If a dose containing Finasteride is given to a pregnant woman it may cause defects to the fetus.