I don't understand how Perdiem and Perdiem plus could be available in Canada, unless some stores just have leftovers on their shelves. In which case the shelf life should be checked. Novartis told me they stopped making the product altogether. They did not say they just stopped marketing it in the US. A few weeks ago, my sister, who also uses Perdiem found a whole case of it in BJ's Wholesale Club. She bought the whole case which cost her over $400. Then a few nights ago she checked the expiration date on the cannisters and found it expires in March of 2003, so it is only good for few months. So anybody buying it, make sure you check the shelf life first.