Started taking glucosamine a few months ago as a preventive measure as I ramp up the running mileage. I don’t have any joint issues that I know of. Just read a report recently however, that glucosamine can be a theoretic source of mad cow disease (BSE) as it is extracted from beef cartilage. There are no reported cases of this mode of transmission, but if a victim eats meat and takes glucosamine it would be very difficult to trace the source. Thoughts out there…