Why Does Propecia Lose Effectiveness?

Hello Doctor,

I have been using propecia for about 16 months with good results, but I’m concerned with the idea of it becoming less effective in time. Is it that the body develops some sort of immunity to the propecia, or is it that other factors contribute to the continuation of hair loss while the propecia continues to lower DHT levels.

I’m considering switching to Avodart, which suppresses a higher amount of DHT in the scalp and serum, and stays in the body longer than Propecia. But I’m wondering how that makes it “more effective” than Propecia if non-DHT factors will still continue to progress hair loss.

I’d really appreciate your advice, since I’m looking to make a move before I notice any more hair loss.

There are generally four causes for hair loss. Genetics (they stay with you for life), hormones (DHT which is central to the hair loss equation can not be fully inactivated in the cells), stress, and time. Medications are not always as powerful as we would hope for. What you are asking really reflects a different and more directed question, which should be:

• Can Propecia retard or reverse the progressive nature of hair loss?

The answer to this question is simply that Propecia alters the rate of the hair loss in its pattern, but it will not change its deteriorating long term course. It is interesting to note that in the early days when I first started to do hair transplants, the patients kept the steady down hill slide to progressive balding. In the recent days, I rarely see the advanced balding arise on those patients who are on Propecia. I have assumed that the Propecia slows down the hair loss. In you question, you ask if you should be concerned with the idea of Propecia becoming less effective in time and that the body develops some sort of immunity to it. I clearly do not believe that any immunityor resistance to Propecia is developed, but without scientific evidence to the contrary, I can not say for certain beyond my personal belief and experience.