My cat gets 2 units of Humilin N daily, the pharmacist is insisting that the medication only has a 6 week life span? I have spoken to many people who said that this is not correct? The medication is helping my cat, what should I do? The cat pee quite alot, prior to getting the medication, his numbers prior to the medication was over 1,000 now it is down to below 500 after 6 weeks. Should I be worried?