Finasteride (marketed as Proscar, Propecia, Fincar, Finpecia, Finax, Finast, Finara, Finalo, Prosteride, Gefina, Finasterid IVAX) is an antiandrogen which acts by inhibiting type II 5-alpha reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT). It is used as a treatment in benign prostatic hyperplasia (BPH) in low doses, and in prostate cancer in higher doses. Additionally, it is registered in many countries as a hair loss treatment for androgenetic alopecia (male-pattern baldness).

In a 5-year study of men with mild to moderate hair loss, 48% of those treated with Finasteride 1mg experienced some regrowth of hair, and 42% had no further loss. Average hair count in the treatment group remained above baseline, and showed an increasing difference from hair count in the placebo group, for all five years of the study. Propecia is effective only for as long as it is taken; the hair gained or maintained is lost within 6-12 months of ceasing therapy. In clinical studies, Propecia, like minoxidil, was shown to work on both the crown area and the hairline, but is most successful in the crown area.

How does Finasteride work?

Finasteride works by blocking the enzyme, Type II 5 alpha-reductase, and in doing so it reduces the level of the hormone in the scalp which shortens the hair growth cycle and allows hairs to revert to a normal growth cycle. This can, in turn, stop hair loss and increase new hair growth in men with male pattern baldness (androgenetic alopecia). Continuous use once a day for 3-6 months is required before benefit is seen, and effects are reversed 6-12 months after treatment is discontinued so continuous use is recommended to sustain benefit.

Side effects

When taken at the recommended dose, the possible side effects of Finasteride are usually mild and generally have not caused the men to stop taking the medicine.

Possible side effects that have been identified with Finasteride include decreased libido, erectile dysfunction, decreased volume of ejaculate, breast tenderness and enlargement; rashes, itching and swelling of the lips and face; and testicular pain. These are reversed after treatment is discontinued.


Some users, in an effort to save money, buy Proscar instead of Propecia, and split the Proscar pills to approximate the Propecia dosage. Doing so is generally considered unadvisable if women of pregnancy age are in the household; this is because finasteride, even in small concentrations, can cause birth defects in a developing male fetus. The birth defects involve the development of male genitalia (no such effects have been noted in developing female fetuses). On most product inserts, it will be mentioned that the dust or crumbs from broken Propecia tablets should be kept away from pregnant women.

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Dr Jonathan's Hair Transplant Result
Dr Jonathan's Hair Transplant Result
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Dr Jonathan began to notice hair loss in his 30s and after gradually becoming more self conscious decided in his 40s to research the options available to restore his hairline. He was looking for a permanent solution and saw hair transplantation as the right route for him, however, as a trained medic...

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