Q: I heard that Propecia stops working after five years. Is this true and why in five years?

A: That is not correct. Although the effects of Propecia (finasteride 1mg) will diminish over time, it does continue to work. Using finasteride long-term will still be better than stopping it at some arbitrary interval. In clinical practice, I often increase the dose of finasteride, after someone had been on the medication 3 to 5 years, to help maintain its effectiveness.

Q: Although I was perscribed Propecia, I have not yet started to take it. I would like to take it now, but my wife wants me to wait until after we have our second baby so as to avoid having the drug in my system when we conceive. She’s concerned that if it’s so harmful to pregnant women, that having it in my sperm is an issue.

A: There is no evidence that if you take the medication it will effect the fetus. However, your wife should not ingest the drug or handle broken pills during pregnancy.

Q: Should I use Nizoral every day?

A: The product recommendation is to use Nizoral shampoo twice per week for dandruff, but many patients prefer to use it daily. Other than drying out the scalp, it is safe to use daily. The 1% formulation is over the counter. The 2% requires a prescription.

Q: I use Nizoral for my dandruff. Does it work for hair loss too?

A: The active ingredient in Nizoral is Ketoconazole. This medication, originally developed to treat fungus infections, has slight anti-androgen action. It is supposed to work in hair loss by inhibiting the action of DHT on hair follicles. Although, in theory, it should be useful for androgenetic hair loss, there have not been conclusive scientific studies to show that it works to treat balding when used as a topical application for balding.

Q: I heard that the sexual side effects of Propecia are irreversible. Is this true?

A: The sexual side effects of finasteride (Propecia) begin to subside soon after the medication is discontinued. This would make sense since the drug finasteride is a reversible inhibitor of DHT. Although it is possible for side effects to be persistent after stopping the medication, this situation seems to be very uncommon and a cause and effect relationship is still in question.