I think that I saw a post on this once before, but am just wondering if there would be any problems to doing this? We tried the Luxura pen, but didn't really like it. We still have 4 pen cartidges in the fridge to use and I just picked up more at the pharmacy (I'd asked for a refill of the vials, but they gave me the pen cartridges instead). Now I'm debating whether I should return them or try to use them without the pen. We always end up throwing out a bunch that is left in the vial each month. It would definitely save some $$ because we get 5 pen cartridges for the same copay as 2 vials of Humalog. We also wouldn't have to waste as much either. Does anyone see a problem with doing this? Any advice would be great.