Can The Body Build A Tolerance To Hair Loss Drugs Such As Dutasteride and Propecia?

by Bradley Wolf, MD

Question: I’ve been taking Avodart for 4 1/2 yrs and got good results until about a year ago when it seems to be reverting back a little. Can the body build a resistance to dutasteride or other drugs and lose some
effectiveness over time? Thanks.

Answer: As you probably aware, clinical studies have not been performed on Avodart with respect to hair loss. We can only extrapolate from those clinical experience and studies done on men taking Propecia. These medications decrease the production of DHT by reducing the concentration of 5-alpha reductase which catalyses the transformation testosterone to dihydrotestosterone (DHT). The body does not build up resistance to DHT blockers. Propecia 5 year study results showed that while Propecia did continue to prevent hair loss, there was a progressive decrease in the amount of hair grown over the 5-year period. See
Avodart could have similar behavior in that less hair is seen over time but as in the case of Propecia, the amount of hair remaining after 5 years is significantly more that one would see if placebo or no medication were taken. So yes, medications can lose a degree of effectiveness over time but in the case of DHT blockers the effect is far superior to not using the medications at all. If you are not using minoxidil, it would be recommended to add this to your regimen. The new foam preparation has been very well received with far fewer side effects than the liquid.

Best regards,
Bradley R. Wolf M.D.
Medical Advisor, International Alliance of Hair Restoration Surgeons

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