Propecia Success Rate vs Placebo

Dear Doctor,
Most of us would agree that wikipedia is one of the most common sources of information on the web. Looking at common hair loss treatments on wikipedia(https://en.wikipedia.org/wiki/Baldness_treatments) I found that the positive effects of propecia are not described sufficiently (as they are in your blog). Moreover, it says that “Propecia has a reported 29-68% success rate (vs. 17-45% in patients receiving a placebo)” whereas your posts report that almost all men have some positive effect. If possible, please clarify.

Several studies were conducted on Propecia (finasteride 1mg) to compare its effect with placebo on hair loss or growth. To answer your question, I present the numbers of one study comparing the effect of finasteride with placebo in the growth of crown hair. In this study, hair growth was compared over a period of 5 years. In this experiment, initially investigators evaluated patients’ hair growth and came up with the below numbers:

The same study was repeated, but this time an independent team of investigators rated standardized photos in a blinded fashion (reviewers were not aware which patient took finasteride or placebo). The numbers were different, but still statistically significant as shown below:

There are some other studies looking at different aspects of hair growth and as a result you may see different numbers. In clinical studies, you may find different numbers presenting the same facts, but if you go to the detail of the study, you will notice that they are not necessarily concentrating on the same parameters. The difficult element not covered by these studies is the ability for finasteride to arrest the hair loss (stop or slow its rate of loss). I am personally certain (in my professional opinion) that finasteride reduces the rate of loss in all men with genetic hair loss.

The drug company (Merck) only report what was studied and can not guess or postulate on what they might logically conclude are probable outcomes in different situations. If it was not studied, Merck will be silent. Being under FDA regulations, they are tightly controlled as to any claims that are made. To get more information about a study, you need to look at the methodology of the study to understand what particular variables are being evaluated. Professionals like me, are allowed to voice their professional opinions and are not held to the same type of restrictions as Merck.