Propecia is Merck Pharmaceuticals’ trade name for finasteride, a drug used for the treatment of male pattern baldness. The mechanism of action was posited in 1974 by a researcher investigating hormones in sexually ambiguous children who found that a deficiency in the enzyme 5-alpha reductase had a number of effects on secondary sexual characteristics, including male pattern baldness. This research was used by the head of Merck’s research division to develop a drug which mimicked the effect of the decreased levels of dihydrotestosterone noted in the hermaphroditic children. Because the same hormone mechanism is involved in prostate enlargement, the drug is also used for treatment of this condition and has also been used experimentally to treat prostate cancer. It is the only drug which is licensed by the US Food and Drug Administration for the treatment of hair loss. It has been demonstrated to be successful in two out of three cases of male pattern baldness.
How does Propecia work?
Propecia works by blocking the conversion of testosterone to dihydrotestosterone (DHT) in the body. This metabolite of testosterone is a key cause of hair loss because of its action in shortening the growth phase of hair follicles, resulting in them shrinking. When the level of DHT is lowered, it appears to block further shrinkage of hair follicles involved in male pattern baldness. In this way, Propecia helps to slow down hair loss and may regrow visible hair. Propecia appears to work only for hair loss on the top of the head and in the middle front of the head, and does not appear effective in halting the loss of hair at the temples.
What does Propecia look like?
Propecia is sold in 1 mg tablets. The tablets are octagonal and orange in color.
Dosage and administration of Propecia
Propecia is taken in a single daily dose of 1 mg. It is important that the drug be taken at the same time each day and taken with a full glass of water. It may be taken with or without food. If there is any reaction to the drug on an empty stomach, you should eat something before taking it. Propecia may need to be taken for as long as three months before there is any visible side effect. If there is no visible effect by the end of twelve months, you should stop taking the drug because it is unlikely that you will get any benefit from it. If you stop taking Propecia after achieving a reduction in hair loss or regrowth of hair, the effect will wear off over the next twelve months.
What you need to know before taking Propecia
Propecia must never be taken by women or children,. Care should be taken in handling Propecia because even dust from broken tablets may have an adverse effect on women. Men who are prescribed Propecia must take it exactly as prescribed, because it will not work properly if taken in any way other than your doctor prescribes.
Common adverse effects of Propecia
Propecia may have a number of adverse effects on male sexual function. These can include erectile dysfunction in up to 18.5% of patients, abnormal ejaculation has been reported in 7.2% of cases, with lesser percentage reports of abnormal sexual function, gynecomastia, pain in the testes and depression. All of these effects have been shown to be reversible on cessation of treatment. In addition, many men have reported lowered libido even after they stop taking Propecia. Recent reports indicate that the drug may cause lasting erectile dysfunction. Although warning of this are now printed on Propecia labels in Europe, Merck still claims on its US product labels that all sexual side effects are reversible.