The reason is the s o c i a l i s t government in Canada used its buying power to force the US pharmaceuticals to either sell to Canada at cost or not sell at all. They chose to sell at cost, but are trying to keep "leakage" to their US customers at a minimum. The FDA thing is an excuse to help out the US suppliers.

I don't seem to have any problem getting my prescriptions filled in Canada. Limited to a 90 day supply though. Buy from reputable stores; all shipments come marked as medical supplies.

AARP is making things worse by blowing this up as a big thing... thus Customs is being forced to stop some shipments.