# Diluted insulin: how to make it last? **URL:** \ **Category:** Insulin\ **Tags:** diluting-insulin\ **Created:** [October 16, 2018, 5:08pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238 "2018-10-16T17:08:52Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Bernus](https://avatars.discourse-cdn.com/v4/letter/b/f4b2a3/32.png) [@Bernus](https://forum.fudiabetes.org/u/Bernus)\ **Post date:** [October 16, 2018, 5:08pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/1 "2018-10-16T17:08:52Z")
Hi @Jen, Did you ever find out about how long insulin lasts once it’s diluted? Thank you. ---
**Author:** ![TiaG](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/tiag/32/594_2.png) [@TiaG](https://forum.fudiabetes.org/u/TiaG)\ **Post date:** [October 16, 2018, 5:18pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/2 "2018-10-16T17:18:08Z")
we were told to remix every 7 days – but I’m _positive_ you can push it beyond that, as there were a few times we couldn’t get the diluent early on in my son’s treatment and we used it past the 7 day marker. We were also told that an insulin vial was no good after 28 days if it was out of the fridge and opened and clearly that’s not true. ---
**Author:** ![Bernus](https://avatars.discourse-cdn.com/v4/letter/b/f4b2a3/32.png) [@Bernus](https://forum.fudiabetes.org/u/Bernus)\ **Post date:** [October 16, 2018, 5:31pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/3 "2018-10-16T17:31:19Z")
Thank you! I tried diluting into new / sterile 1.8ml minimed reservoirs and noticed that only once it lasted about a month but twice now it only lasted about a week, all the time refrigerated. To test if it was the reservoirs that were causing the issue, I used the reservoirs to store undiluted Regular insulin and those have lasted for months. So could it be the diluent? Do you open a new diluent vial every time you dilute or do you use the same diluent a few times? I only use 20 units of diluent to dilute my R, so throwing it away seems like a waste. Thank you again. ---
**Author:** ![TiaG](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/tiag/32/594_2.png) [@TiaG](https://forum.fudiabetes.org/u/TiaG)\ **Post date:** [October 16, 2018, 5:39pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/4 "2018-10-16T17:39:15Z")
the diluent, on its own, should last quite a while, even opened. I believe it’s the mixture of the diluent and the insulin that becomes unstable. But I could be wrong about tht, so don’t quote me. The other thing is that when we were using diluted insulin we were not using it in a pump, just syringes. The diluted insulin is going to be warmer if it’s up against your body, and so it may last less long that way. ---
**Author:** ![TiaG](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/tiag/32/594_2.png) [@TiaG](https://forum.fudiabetes.org/u/TiaG)\ **Post date:** [October 16, 2018, 5:40pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/5 "2018-10-16T17:40:00Z")
also it may be a waste but from what I understand the manufacturers are providing the diluent free, so it shouldn’t be prohibitively expensive to use a new vial for each change out if you want. ---
**Author:** ![Bernus](https://avatars.discourse-cdn.com/v4/letter/b/f4b2a3/32.png) [@Bernus](https://forum.fudiabetes.org/u/Bernus)\ **Post date:** [October 16, 2018, 5:42pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/6 "2018-10-16T17:42:26Z")
I don’t use a pump so the body temperature shouldn’t be a problem. I shall continue testing. Thank you again. ---
**Author:** ![Michel](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/michel/32/387_2.png) [@Michel](https://forum.fudiabetes.org/u/Michel)\ **Post date:** [October 16, 2018, 11:46pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/7 "2018-10-16T23:46:28Z")
Welcome, @Bernus! I edited your first post to make it a callout to @Jen. I also gave you your own thread 🙂 ---
**Author:** ![Eric](https://yyz2.discourse-cdn.com/flex030/user_avatar/forum.fudiabetes.org/eric/32/9209_2.png) [@Eric](https://forum.fudiabetes.org/u/Eric)\ **Post date:** [October 17, 2018, 3:47pm UTC](https://forum.fudiabetes.org/t/diluted-insulin-how-to-make-it-last/5238/8 "2018-10-17T15:47:42Z")
> [@Bernus](#): > > Did you ever find out about how long insulin lasts once it’s diluted? Hello, I was planning on testing this out a while ago and I diluted some NovoLog 5 months ago for the purpose of a test! When I saw your post, I thought today would be a good day to check it out. **50% NovoLog:** ![image](https://canada1.discourse-cdn.com/flex030/uploads/fudiabetes/original/2X/9/97a3f1222f7399c4fa7115cdeea200a9139783a4.jpeg) **Diluted on May 20th (5 months ago at the time of this post):** ![image](https://canada1.discourse-cdn.com/flex030/uploads/fudiabetes/original/2X/2/2cb1b88d5d3470b505cddb201e199fac58f381ac.jpeg) **And…** ![image](https://canada1.discourse-cdn.com/flex030/uploads/fudiabetes/original/2X/9/99ee4101915f7efc1ee1b386b43b64ae8436de6f.jpeg) ## Still works! I was actually 66 at the time of this Dexcom picture, not 84. The diluted stuff dropped me right down. Anyway, how long does it last? At least 5 months! Probably much longer.