Does Invokana have a short shelf life? I started taking it mid July and in August landed myself in the hospital with sever dehydration. As a result I was off Invokana for three weeks and then restarted at 100mg for 6 weeks. I am now back on my 300mg and finished the original prescription from July. It didn't seem to working near as well as before. Yesterday i refilled my prescription and my numbers are why down again and the side effects are back in full swing.

So my question is does the pill become less effective if it sits for a month or so. My insurance company wants me to order 90 day supplies but if it less effective then that is a waste.