It makes no difference if you believe it or not. Its already been well documented.
Because if you take a medicine for 22 years, depending where you live and what brand you are taking, there will be points where the brand you are on is discontinued, in my instance when that has happened, its then been the case that I've had to cycle through 4 or 5 brands before I can find one that is able to stabilize my hair again, as usually if the first brand I switch to is ineffective it will start dumping the entire front two thirds of my hair onto my keyboard within a few months.
Already been countless others reporting shedding restarting after a brand switch.