Lantus goes bad after 30 days?

I’m new to using insulin, so if this question appears ignorant- it’s because I AM ignorant. I don’t have health insurance, so I am very cost conscious of my Diabetes medicine and supplies. Anyway, my Lantus basal is only 17 units every night. So I have this huge supply of Lantus that is less than half used, yet it is older than 30 days now. I don’t want to throw it away as it seems like a waste of money and insulin. Is it okay to keep using it, or do I >really< have to throw it away? I want to save money. Yet I don’t want to hurt myself using old/bad insulin. Any help here is appreciated!

Charles, here is a discussion with many replies that may answer any questions

The maker of Lantus (Aventis) has studied the effectiveness over the range of conditions and essentially assures you that the Lantus will be still good 30 days after opening. After that, all bets are off in terms of what Aventis assures. That being said, I would actually believe that this is for worst case conditions. If you read (, there is a detailed discussion of storage and handling for insulin and it indicates that the two main factors degrading the effectiveness of lantus is temperature and light. My bet would be that if you kept the lantus in the fridge all the time away from light, it would probably be fine for longer than 30 days. But understand that if your fasting levels start to rise, you should immediately suspect that the Lantus has gone bad. Also, if you notice any clumping or congealing, the insulin is bad and should be discarded. Any medical professional would likely advise you against skimping in such a way, but of course they would also tell you not to inject through your clothes as well.

I think bsc has it figured. Put it in its box in the frig. - in the back of the frig. That will reduce light from the times you open your frig. Use it as long as you can til you find your BGs going up. You’re not alone.
Bernstein has a documented way of reusing insulin syringes, too, you can use if you’re short.

Charles, I get a 90 day supply of Lantus when i get refills, I always keep my unopened in the fridge until needed, I still carry my opened lantus in a cool pac travel case when I go anywhere and then place it back in the fridge when I return even thou they now say it can stay at room temp for thirty days. I would think that if the Lantus went bad my insurance company and doctor would not give me the 90 supply. Just a thought …

I have been without employment and medical insurance going on 14 months now. Discard after 30 days refers to opened vials of Lantus, not those still sealed and in their boxes. I have tested 10 open vials past the 30 days, all under constant refrigeration, and viability varies. 45 days of use seems fairly consistent, but I had one go bad at 28 days. I also learned as Lantus effectiveness fades, increasing the dose by 2 to 4 units was adequate compensation. As long as you closely monitor your blood glucose and are prepared to compensate highs with your short-acting insulin, the consequences are in your favor. I am spending hundreds of dollars monthly on insulin and test strips, so reusing lancets and syringes doesn’t bother me. I truly miss having insurance.

Would it potentially be cheaper for you to switch to the Lantus pen? I used 12 units of lantus a day, and the pen lasted me 4 - 5 weeks. They are packaged 5 in a box. So, buy one box and it would last 4 months. I am not sure anymore of the retail cost of the pen.

Lantus loses potency after 28 days, when opened. Once you see numbers climbing, you’ll know it’s not working well.

I was in a similar financial situation and got 6 vials of Lantus. I left them in the fridge (except for the open one) and made sure the fridge stayed a few degrees above freezing. Look at the temperature requirements because I don’t want to give bad info. The longest I’ve ever used a vial is about 37 days and had no trouble even without keeping in a cool pack. Like the others said, though, watch your fasting sugars. Take good care, Charles.

Depending on your income, you could be eligible for a patient assistance program through the company that makes Lantus, where they would send you your medication for free. I used that program a couple of different times while I was in college and had no health insurance, and it did a lot for my peace of mind, knowing that I could get insulin, and didn’t have to potentially use insulin that wasn’t as potent as it should be, just to lower my costs. I got pretty good at using insulin on a tight budget, and, like most other people here, notice that you can make insulin last longer than the manufacturer says if you keep it refrigerated, etc. Good luck!