Propecia Success Rates — What’s Your Take?

Hello dr,
I have a question which i have searched all over the web seeking for answer and couldnt find it. i know merck say propecia have around 80% in stopping any further loss, my derm said that in his experiece it has only around 60% in doing so, I would really appreciate knowing what u make of the success rates and based on your experience what would u say the rates truly are in stopping any further loss?

I tend to see that the rate of Propecia halting hair loss is quite high in young men, but I don’t have actual percentages. I do not make statistical analysis of the men that I prescribe Propecia to.