Hi Doc,
Two-part question for you: Does genetics determine what age we get MPB (for example, was I destined to start losing my hair at 21), and also, how does a mans’ age at which he begins balding affect his final pattern, if at all?
The start of hair loss is mainly genetic (according to our general understanding), but recent studies suggest that diet, lifestyle and other factors such as stress, will also impact the start and rate of balding. It is believed that our final pattern is predetermined. That means if it is meant to be a Class 4A (see image at right), then the variable will be the rate of achieving that final pattern. A Class 7 will not evolve out of a Class 4A genetic pattern if the genes are not lined up that way.