Omnipod: three bad sites on a row

We ran into a weird problem yesterday involving a sequence of bad sites. It puzzled me so much that I thought the story might be helpful to others.

We had an occlusion very early morning, and changed to a new pod. The pod worked fine, but reaction to insulin activation was a bit sluggish. Then, at dinner time, we programmed a bolus and waited for activation. But we never turned the corner. My son’s BG remained nice and even, and never went down. After 1 hour and 40 minutes, we programmed a second bolus for dinner still, and the same thing happened. So we changed the pod and tried again. The same thing happened to the third bolus. By then I was gobsmacked. I was starting to question everything: could it be the insulin? What if the PDM was only able to program basals but no bolus? Do we have a bad lot of pods?

I was concerned, since I felt that we had no control over BG right then. I spent time on the phone with Omnipod. They encouraged me to switch to a pod with a different lot number. By that time it had been close to 5 hours: my son was really tired, and had not been able to eat any carbs. His BG was still steady, trending very slightly down after having taken 3 consecutive dinner boluses with no carbs ingested.

So I decided to first test the insulin alone, to rule that out, and to call the big guns. We injected 2 units of insulin from a pen, and waited it out. I also called @Eric (the big gun) I asked him what he thought. Eric believed that it was unlikely to be the pods, the PDM or the insulin. He felt it had to be a site issue. He suggested that, in my pod change, I look carefully at the canula when removing the pod, then test the old pod once it was out to validate that it was working.

In the meantime, the pen insulin activated and my son was able to finally eat something. Then we removed the pod carefully (without deactivating it), pulling it off the back to be able to have a good look at the canula still in the flesh. The canula looked good but there was some blood right around it. Once the pod was totally off, we programmed a bolus. We hear the old pod click and saw the insulin come out. So we knew the pod was good—and yet my son was not getting insulin. It had to be a site problem.

So we set up a new pod (from the same lot number) and my son turned in for the night. He was reacting well to basal overnight, then, when breakfast came, his insulin activated fine.

So, in the end, what happened? It seems to me that all three pods had a site problem. The first one may have had a slightly bent canula: when I looked at it through the window, it was in, but did not look 100% symmetrical. The second one seemed perfect, but there may have been some mysterious positioning issue. The third one had some blood right around the canula, which may have caused absorption problems. Either way, all three are likely to have been site issues, as @Eric suspected (although, for the second one, it really really be any other cause, including a weird pod failure).

As a data point, we have only have one site issue every since we started on the Omnipod about 6.5 months ago. So, to me, the lesson of the story is that, of all problems we are likely to encounter, site problems are the most likely: it is clearly possible to have multiple site failures in sequence, even though you change the site every time. I still find it hard to believe that we could get 3 site failures on a row—yet it is most likely what happened.


Thanks for sharing. We have had similar issues lately. Pod sites would fail for no reason, no occlusion alarms ever issued and we couldn’t figure out why. We were both also hesitant to chalk every incident up to a site failure early, which led to prolonged high BG. We were following the generally suggested protocol of pinching up a little bit while holding down the cannula end lightly during insertion, not bolusing more than five units, etc. By the time we realized that there was a problem, it was often hard to determine how much insulin was actually on board as it wasn’t really working, and then we would use the pen to inject more insulin in a different site, and wind up with Boomarang blood sugar as I like to think of it.

Also, there was clearly an insulin sensitivity issue going on. We solved it by switching from Humalog to NovoLog and that has made a big difference. We were routinely not getting to day 3, or if he didn’t swap the pod he’d be running in the 170-300 range for a long time. Switching early helped, but it really felt like the insulin just didn’t work anymore. We have not had the same problems using NovoLog.

I also reached out to @Eric and got good advice!

Switching to NovoLog has made all the difference, BG isn’t perfect, but it is certainly better. And we are getting to day three quite frequently.


I have also run into that periodically. Seems like the law of averages will expect that to happen from time to time. Still–pretty frustrating when it does.

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I am glad that worked out for you! I definitely like it much more in the pump than Humalog.


That’s interesting. Histprically I’ve used novolog, the first time I tried humalog (MDI) I didn’t like it and was certain it didn’t work well for me. Fast forward a few years to when I just realized the same box of humalog expired a year ago and I better use it up or it’s going to go to waste, and now I’m thrilled with how well it’s working…


Expectations? :slight_smile:

For clarification, I have used Lilly insulins (Humalog, R, and NPH) for the past 40+ years. I still like it, and still use it for MDI. It is fine, works great and is extremely resilient to being unrefrigerated and it seems to last forever. I can totally ignore the expiration date when I use it for MDI.

But… for whatever reason, Humalog on 3 day of being in a pump sometimes flakes out. Could be the absorption of being spit into the same location for 72 hours, or whatever.

So that is the only complain I have with it.


This should be printed on every pump out there. To be honest, the tech is amazing, but almost every problem we have faced has been a site problem. It used to take us time to try and figure out what is going on, now, if we even slightly suspect we have an issue of our pump not working, we rip the site and replace.

For reference, we have lots of times our sites go down on day 2, but Humalog sits in our pump for at least 6 and sometimes 9 days with no problem.


Have you compared Humalog with NovoLog for site issues? It seems to me that the insulin stays fine in the pump for both (i.e. if you took it out of the pump reservoir and injected it, it would still work). But the site issues exist more with Humalog. It might be a useful experiment if you can score some NovoLog. I can send you a new vial if you want to try it.


We have not tried it, I will give that a try. I have a business trip to the great white north in July, so I will grab some then. We probably wouldn’t try the experiment during baseball season anyway. Thanks for the offer! Very much appreciated.


what constitutes a bad site? is it a “scared” area of insertion? is it an overloaded area of pooled insulin? how much do you actually rotate ? how far apart do your insertions need to be from the previous one?

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Goodness, @daisymae, I am just realizing this question of yours has remained open all that time!

Some sites do not appear to provide smooth absorption/ distribution of insulin. I am not sure anyone knows of a good classification of all the reasons, but I can think of (a) scarring, (b) being on top of a recent site, © “sponge effect”, (d) age of site, (e) bleeder, (f) leaker, (g) muscular location. I am sure there are plenty more.

(a) If you had an infection, a cut or other trauma, the scarring may be impacting the distribution of insulin. Using a pump for many years without good rotations may be a cause. I have been told that such scarring may go away after a few years, allowing you to possibly reuse old site. I don’t know first hand. We have a site infection that resulted in such scarring, a site we don’t use.

(b) if you reuse the same site or you are too close to a recent site, the constant dripping of insulin may have somewhat compromised the tissues and make the links ation less propitious to good insulin permeation . Our rule of thumb is to keep at least one inch away from a recent site in the site rotation.

© I have been told that it is possible to saturate your tissues with insulin. The sponge effect is that, when your tissues are full of insulin, they can’t take more, like a sponge, so your next inject tions are ineffective. We have seen that phenomenon happen after several big injections. Now our rule is to use pens for anything 5U and over.

(d) As your site ages, it gets less able to absorb insulin, with the same result. Many old timers used to keep sites for up to a week, but many have also said they got a lit of scarring out of it. Many people, such as @Chris or @Jen, don’t use even a site for 3 days for that reason. We have seen what we think are 3rd day problems before.

(e) If, under the adhesive, there is some bleeding, the blood can sometimes wreak havoc on the eficiency of the site. We have had many slightly bleeding sites with no problem, but a couple of bad sites where we found significant bleeding afterwards.

(f) It happens that some insulin leaks around the canula end and comes back up to the skin and adhesive. I think it is @Beacher who has discussed this phenomenon at length. We test for it by smelling the adhesive for insulin.

(g) I also figure that there are some sites that may be too bony or muscular to allow for good distribution. After all, there are skin locations that will not provide the 3D geometry required for solid 360d distribution of insulin.

Finally, for your rotation question: we have had several threads on site rotation in the past, some of which have great rotation maps. As for us, we use a 12-site rotation across the arms and the love handles.

I am sure I have missed a bunch of info! So if anyone wants to complete it go ahead :slight_smile:


I rotate sites not for scarring issues but for allergy issues. I’ve never been able to wear a site for more than two days without issues, but after a few years of pumping with plastic infusion sets, that issue got worse and worse until sites weren’t even lasting a day. If I leave a site in for too long (sometimes even just 12 hours when my allergies are really flaring up), it becomes red, inflamed, itchy, and slightly painful (if you have ever had allergy immunotherapy, it feels exactly like an injection site reaction) and just stops absorbing insuln. Most plastic infusion sets don’t even last 24 hours, and metal sets typically last 24-48 hours, but sometimes less.

This is actually the reason I’m not even considering the OmniPod. When I discovered I was reacting to plastic infusion sets in 2011, I was able to switch to metal infusion sets, which thankfully I have continued to tolerate well. But if I ever did start reacting to metal infusion sets, I’d be able to try various sorts of plastic sets to see if there was one I reacted to the least. With the OmniPod, I’m stuck with the built-in infusion set.


Michel, this was one heck of explanations. lots of possibilities for everything.

i change my pump site every other day. this has seemed to help keep me from getting scar tissue or absorbtion problems. i rotate and rotate and rotate. it works. its difficult being as skinny as i am to avoid getting scar tissue, that’s why i took eric’s suggestion that i try changing sites every other day as opposed to every third day. it has really made a difference.


I know this is an old topic but… I am starting to experience site issues every time I change my pod. Within 24 hours I experience discomfort where the cannula is. When removing the site it has a bump and is red. Within 2 hours the bump is gone and within a day no redness, however I have a mark/scar. I spoke with Omnipod today and they suggested I speak to my endo. They were not able to offer any suggestions on how to prevent this?

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That is troubling, especially since there really isn’t anything you can do to intrinsically change the site on the Omnipod as compared to tubed pumps. I don’t have a solution for you, but issues like what you are facing is why we now change sites every 48 hours, as well as having absorption problems on day 3.

This happened to Liam early on (the red bumb) and we figured out that what was causing it was having insulin around the insertion spot on the underside of the POD. (i.e., when filling the POD and removing the syringe, some insulin falls around that hole. We started cleaning that spot with a clean cotton ball and then we stopped seeing that red spot.

We also have a “rotation schedule” to be sure each spot only gets hit once every 24 days (4 sites, 2 directions (up and down on each side. We rotate as follows:

  1. Right thigh side (side of his thigh) cannula facing up
  2. Left thigh side cannula facing up
  3. Right thigh upper (top of his thigh) cannula facing up
  4. Left thigh upper cannula facing up.
  5. Right thigh side cannula facing down
  6. Left thigh side cannula facing down
  7. Right thigh upper cannula facing down
  8. Left thigh side cannula facing down.

In this way, 8x3 = 24 days before we are back to Right thigh side cannula facing up.

These things have helped us avoid site sites in Liam.

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What insulin are you using?

I am using Humalog. Which I have used for many years. Thank you for the suggestions. I will try 48 hours, cotton ball and increasing my rotation. Since moving to the omnipod I rotate much more than I did on my Medtronic, but still favour my stomach. I really hope that this can help. I really like the Omnipod compared to my old veo.

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I used Humalog for 44 years (or the Lilly brand of insulin at the time before it was called Humalog).

When I started using a pump, I found that Humalog was not a good insulin for me to use with the pump. I was much more successful when I switched to NovoLog.

Humalog was fine for injections, but just wasn’t good for me for pump use.

I am not the only one. I think @TravelingOn and @T1Allison can vouch for that same thing.

You may want to give NovoLog a try.

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