Is it true that minoxidil only works on the crown (vertex)? (photo)

This man is showing that minoxidil has worked on his hairline. The reason that most say that it only works on the crown (vertex) is that the FDA only got approved for claims on the crown (Vertex) when the drug got approved. It clearly works sometimes on the hairline as many men will tell you so and it works well in the crown for many men.