Question for anyone who has had poor absorption with their pump

I know I’m not the only one who has had the issue of their sites prematurely failing because they stop absorbing well, so i am wondering how many people have switch insulin and found better consistency and longer lasting infusion sites?

I have been taking Humalog in a pump for about 20 years, and in the past year or so I have had very rapid failure of my infusion sites. Like clockwork after about 1.5 days it goes from working fine to just not absorbing at all it seems. There are no leaks, but it just pools up under my skin. It will eventually absorb, but I think it takes so long that it basically goes bad and doesn’t do anything. If i change my site I will be find for another 1.5 - 2 days. This also causes a lot of inconsistency, so I will have great BG one day, and then it will just go all to heck on the second at some point, which then means it takes a long time to get back in range and steady.

I have tried various infusion sets and even fresh areas on my body with roughly the same results (maybe an occasional lucky break once in a while, but not repeatable), so I have to imagine it is something to do with the insulin. Others have mentioned it could be the case as well.

I am just curious who has experienced the same thing, what insulin did you switch from and switch to, or if that didn’t help is there some other solution to the same issue you found?

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I have noticed the pooling under the skin, and I have noticed that absorption may not always be as good after the second day, but I have not changed insulin to see if that makes any difference. One thing that has made a difference for me is not doing large boluses. If I have to bolus more than 6 units, I do an extended bolus with 6 up front and the rest over 30 minutes. This appears to lessen the likelihood of pooling or leaking, and I’m usually able to get the full three days out of my site (Omnipod).


what brand of pump? AFAIK, the MM is the only pump on the market that does a very slow bolus.

I know you said various sets, but have you tried Sure-T’s (Contact Detach is the Luer lock equivalent)

NOTHING WRONG WITH CHANGING YOUR SET EVERY 2 DAYS if that’s all you need to do to fix the issue!

What amazing timing: yesterday I suddenly wasn’t absorbing my insulin (it was the second day of using one infusion site, and originally I could go more than 48 hours with good absorption on my Animas Vibe). I changed my site and still was staying between 250 and 275 and felt rotten; I increased my basal settings by 50% and bolused the correct amount but my BG wouldn’t come down. Removed my second infusion set and there was so much bleeding. It had also really hurt both times and I suddenly realized I’ve been exercising more and might need to change to my stomach (instead of upper buttocks-- sorry if tmi --and side). My stomach is working better as there’s less muscle there (and I had stopped using my stomach during my pregnancy, then forgot it was an option… 5 years ago!!!). It will be interesting to see if tomorrow is better with this new infusion site on my stomach…? Couldn’t agree more about bolusing, Beacher-- the extended bolus or combo bolus where a percentage is taken upfront and the rest over the next 10-30 minutes works for me, and I usually only bolus 1 unit or less upfront, otherwise it is harder to absorb, and more painful.

These are great questions about changing different factors to see if there are more solutions for improved absorption… Look forward to hearing what others have found!

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Oh, yes-- I forgot that the animas vibe has two delivery speed options: normal and slow, but I don’t know, as Dave44 says, how slow this option really is in comparison to MM :wink: It definitely improved my experience to slow the delivery down at least a little bit. Thanks for bringing this up, Dave44!

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Yes. I have had more success with NovoLog than Humalog. I still have occasional day 3 crappiness with NovoLog, but not nearly as frequently as I did with Humalog.

I have experienced the problem, usually after 2.5 days. I’ve gotten in the habit of changing sites around 2.5 days apart most of the time. The phenomenon seems closely linked to the amount of insulin I’ve pumped through a site. After higher-carb (and, therefore, higher TDD) days, I see failures in as little as one day. Lower-carb days see more successful absorption - and longer life of a site. If I’ve had several low-TDD days in a row, I’ve had sites work well into the third day with no problem – I don’t let it go longer than 3.5 days and even that rarely.

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animas set to SLOW bolus is 1U every 5 seconds. FAR faster than MM. You could get 12 units per minute. It seems like it is an eternity for a MM to bolus 12 units. :slight_smile: Any bolus =>10 U on the MM is faster than those under 10 but I forget the exact speeds.

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Wow! Thank so much for this info… Animas won’t be selling insulin pumps any more and Medtronic will be taking all Animas customers, so this will be a change to look forward to sometime in the next couple of years!

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Interesting! So maybe I will try out NovoLog. Do you think it is more easily absorbed in larger boluses than Humalog? That is, is the problem with the insulin, not with the size of dose?

I am getting ready to switch from Humalog to NovoLog so I hope I get the same results.

I can’t say much about why I have had better results. I don’t know any reason. Supposedly the two insulins are almost the same thing. But after enough time using both, I am much more comfortable with NovoLog lasting for 3 days. Best advice I can give is to try it and see if it works better for you. You can get it cheaply from Canada, so if you have insurance issues you can at least try it that way and see.

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Probably a combination of both bolus sizes and insulin. I went from Humalog to Novolog due to absorption, and eventually ended up with Apidra. The Apidra works much better for me, but I see a slow down with it over time as well. I will likely end up going back to Humalog (due to insurance changes) and will evaluate the change again.

The biggest issue is large boluses. Forcing too much insulin damages the subcutaneous layer. So the suggestion by @beacher is a good one, and is what MM actually recommends:

All the current pumps (Tandem, MM, and Omnipod) have an extended bolus feature. Set the 6 units for immediate delivery, and the remaining bolus to occur over 30 minutes. It helps.

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Yes, I had some problems with this almost two years ago. Prior to then, I didn’t realize the hazard in dosing more than a few units at time. After doing more research, I realized this was likely the culprit.

I got so frustrated with the inconsistent sites that I ended up switching back to MDI, and I’ve remained on MDI since. I started using a cgm a couple of years ago which also probably helped me realize some of the problems with absorption with my pump. I had a diabetes educator tell me that most people absorb much less insulin by the third day of a site. I found this idea very frustrating because it’s difficult to manage the minutia if your insulin absorption is going to vary from day to day (if the site works at all!).

Anyway, I found that I also prefer only having the cgm attached to my body and no pump. I feel like I can maintain control much better with MDI and the cgm than with a pump without one, and I really don’t want to have both attached to my body at once (though I’m glad that works well for some people!).

I hope you find a solution that works well for you! I again echo everyone here in saying that the amount of insulin you’re giving yourself has a huge impact on the efficiency of the site.


I have the same issue with absorption by the end of the 2nd day with any and all infusion sites. I have used both Humalog or Novolog, I’ve used three different pumps from 3 pump companies (Omnipod, Medtronic & Tandem). I have also tried many different infusion sets to see if that would make a difference. Because I have a CGM (Dexcom) I am able to see down to the hour almost when my blood sugar starts to rise due to poor absorption. It is my opinion that somewhere between 36-40 hours my body starts ‘rejecting’ the cannula and grows around the cannula for lack of a better word. My only solution is to change to a new infusion set at a different site before the end of the 2nd day. I am relieved to know that I am not the only one who struggles with this issue.

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This is actually a very common problem. I have never been able to tolerate 3 days between changes. Site degradation can be caused by either irritation of the tissues around the cannula or by denaturation of the insulin around the cannula. Some of the analogs are worse than others. Apidra is prone to denaturation and site irritation problems with Fiasp are being widely reported. Best strategy is to change the cannula more frequently (if you need to do this after 36 hours, then that is what you need to do)

I have been experiencing the same problem with infusion sites. Good for a day (or maybe only a few hours), then I get unexplained lows. After that, I will go high and won’t be able to bring it down with bolus from my Animas pump. I had this problem with the previous two pumps also. I am on Medicare, which complicates insurance things, so changing anything is complicated. I have finally convinced them to send me more supplies than Medicare normally approves. I have been on Novolog and Humalog over the years with no apparent difference.

The only thing that I can add to the discussion is that I also have Chronic Lymphocytic Leukemia, which means my white blood cell count is high. I had problems with sites before that, but I thought I would add to the discussion.

Me too! After trying every single infusion set, every available location, 4 different pumps, I have the exact same problem. I even pumped some insulin through the infusion set that stopped working and the insulin flowed normally. After 36 to just under 48 hours the infusion set stops absorbing and sits there as a tiny lump. This lump dissolves sometime later. This makes nearly impossible to pin down an accurate basal or carb ratio. 2 different endos and 6 different diabetes educators all tried to show me how to fast and test to pin these numbers down but it varies wildly from one day to the next.

Right now, I’m on the 670g which has helped but if my bg starts rising unexpectedly, I just rip out the infusion set and replace it.

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Years ago I used to have insertion sets that had one tubing, 2 sets. Is that still available does anyone know?

Hi all, thanks for the replies, sorry i was out of town and didn’t ever get a chance to reply.

I have the t:slim X2. While i wouldn’t say that it has a special slow bolus setting exactly, it does pump fairly slowly. In addition to that there is also the extended bolus setting and you can set it to either be multiwave (a certain percentage immediate, and the rest over a specified time), or all of it over an extended period.

I am currently using the Contact Detach, which has had the best results so far. I don’t exactly have a problem with changing them every 2 days, which I already do, but that doesn’t quite solve the issue as lasting 2 days can be a stretch. If I could get all the way through 2 days reliably so that I could plan for the changes better that would be great. Currently the sites will almost randomly start failing some time between then, which is a big problem as I don’t know when it will happen and end up stuck in a situation where I can’t change it out and my BS level continues rising. The current supplier I am forced to use also doesn’t want to ship me enough infusion sets right now to swap out every 2 days or sooner and still have some extras. I could maybe barely make it if I could go 2 days. Hopefully I will get rid of them soon…

I am planning on asking to try some other insulins, but at the same time I feel like this might be what is happening for me. I am also going to start using more extended boluses and see how much that helps.