Are hair loss medications like Rogaine and Propecia as effective in African Americans?

Yes. There has been relatively equal data showing that there is no difference in the efficacy in both Rogaine/Minoxidil and Propecia/Finasteride in regards to the prevention of male pattern baldness or androgenetic alopecia.  I personally have had many African American patients over the years taking either one of those two products or both together have had equally successful results in those patients as compared to those patients that are non-African American.