You can always push for it to be a 28 day supply. Technically the 10ml vials are only rated for safety for 28 days. Check out what the CDC says about multiuse vials. That means you can push for a new vial every 28 days. Just tell your doc you would be more comfortable with a new vial every month due to sanitary concerns and don't mind paying each month, and tell him that you just want one vial per month rather than a bunch of little ones. As long as your doc and pharmacist are on board, you should be able to get a new 10ml vial every 28 days. (you might have to do some pharmacy shopping if your pharmacist is not comfortable doing this).