Untethered regimen (pump and Lantus) experiment

I have a bunch of old Lantus, Apidra, and Tresiba sitting in my fridge that I would like to use up. (Levemir would be my preferred insulin if I were doing MDI.)

A year or two ago I tried the “untethered” regimen of taking 50% of my basal as an injection of Lantus and 50% from the pump. I didn’t notice any huge benefit so gave up after a few weeks.

But since I have Lantus to use up, I decided to give it another try. Especially now that I’m using Fiasp, which has the downside that I can’t disconnect my pump for even half an hour without a very noticeable impact on my BG. And if a pump site “wears out” after two days and I don’t change it right away, I end up fighting highs for hours. I’ve been having more instability in my BG lately, and I felt like maybe small interruptions in insulin delivery (from disconnecting, site issues, absorption issues) combined with the faster onset and tail of Fiasp might be contributing to this issue.

This time instead of taking 50%, I just took five units of Lantus. I didn’t even really change my basal rates, just injected the five units on top of the basal I was already taking. I think maybe I may have lowered basal by 0.2 units an hour, but I didn’t keep records and I was also making other basal tweaks for overnight, so I can’t remember. Okay, so not very scientific of me, but I wasn’t planning on posting about this, I was just doing it for personal curiosity but have been surprised at the impact.

My BG has been near perfect for the past four days. I thought I might have problems with lows, but I haven’t. I’m still able to suspend my pump for half an hour to get a small bump up in BG, but the bump up is considerably less than what it used to be (which is good). Disconnecting for showers with creates a flatline rather than a spike (even when I don’t bolus to cover the disconnect period). It seems to me that the difference between having five units of insulin in my system at all times and having zero insulin in my system at times is surprisingly large. (I do still often have to do follow-up boluses about two hours after eating because Fiasp wears off too soon. Experimenting with combo boluses will be next.)

I have wondered if maybe the Lantus I’ve injected has gone bad (since it’s sat at room temperature for several months) and maybe that’s why I haven’t really had an issue with lows despite not changing my basal rates. But I don’t know… At five units a day this cartridge will last me about two months, so I guess I’ll see when I inject with a new cartridge of Lantus out of the fridge if I continue this for that long. (Or I guess I could just inject with a refrigerated cartridge right now to see if there’s any difference…).

I think some others on FUD have experimented with the untethered regimen, so I’d be curious of others’ experiences.


That sounds pretty awesome. For basal, I have always thought that the way the basal insulins unwind slowly in your body it works more consistently and is less susceptible to site issues than a pump giving a rapid insulin.

I think your experiment is great. Thanks for sharing!

@Chris’s son does untethered for baseball.


We find that untethered for Baseball is awesome. Just before the season we figure out how much basal is enough to keep him flat to a very slight rise with exercise, and then we inject that every day, and use the pump to make up the rest.

During the season, he arrives for a practice or a warm-up for a game, removes the pump, and then based on effort, either reconnects and gives a small amount of insulin while in the dugout, or eats his way out of a low if it is a particularly intense game.


I tried to use an hour and a half suspend on the way home today and that seemed to work pretty well, it kept me stable during my walk home and then I had to bolus a correction after getting home (which I always have to do after suspending my pump). I’ll be curious how high I actually go from the suspend, because if I’m able to stay in range—which it looks like I might!—then that’s a HUGE improvement (the commute home has been an ongoing struggle for me for literally four years or so).


If by suspend you mean set to zero basal, and afterwards you always need a correction, what happens if you set your basal to 10% or 20% instead of zero?

Usually anything below about 50% requires a substantial follow-up bolus, even with exercise. I use -10% and -20% routinely, but I don’t use anything lower than that unless I’m specifically wanting my BG to rise.

Wow that’s really interesting, as I just recently started pumping Fiasp and also have quite a bit of emergency back-up Lantus on hand. Funny thing, I hadn’t noticed the correlation with highs and disconnects until you mentioned it. But just this last hour I set a very low temp basal in anticipation of my homebound bike commute, and was really surprised how quickly my BG came up (too much, actually–I just canceled the temp!). I think I’d actually noticed it before but didn’t relate it to Fiasp. So thanks for that! I’ve also noticed that my sites really die on day three. I used to be able to wait to the end of the day if I still had plenty of Novolog in my reservoir but, like you, I get stuck fighting highs all day if I don’t swap it out first thing. Kind of annoying but man do the benefits outweigh the minor inconveniences with this stuff.

Dunno if the hybrid-basal with Lantus would fix that problem but your experiment sure sounds interesting. I might give it a try just to see what it’s like. I’m kind of a big guy so I’m guessing five units might not be enough to see any effect. What was that relative to a full dose, percentage-wise, for you?


Damn, we are on the same channel today. Me too–one of the major reasons I wanted to try Fiasp.


@drbbennett, five units is currently 12% of my basal insulin.

If you do try it, I’d be really interested in how it works out for you!

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Also, today was day two of not going low during my commute home. Though I did have to eat one glucose tablet to prevent a drop. Still a vast improvement!


I just downloaded my CGM data and literally almost cried. LOL. It’s so good. So stable. I’ve never had this good control for so long. Such a dramatic difference. I think this is sort of like an artificial honeymoon I’ve created here. I’ll wait for the week to end on Sunday before I post the stats, but they are unbelievable for me.


Saw your post on flatliners and your numbers are looking great.

I sense an A1C in the 5’s in your future…

I don’t see my endocrinologist for six months, and unfortunately he didn’t give me a form for an A1c test in three months. But if this keeps up, I’m going to ask for one from my GP during the summer just so I can see any progress.

You see the same endocrinologist as me. Do you see him every six months? And, if so, do you get an A1c done every three months? I don’t mind seeing him every six months, but I would like to test my A1c and thyroid every three months just to make sure nothing’s gone awry. Something I’ll probably ask him about in the fall.

Just ask for him to email you an undated requisition and you can use it as many times as you like (if the system in BC is the same as Ontario).

Here they take the form and keep it, so as far as I understand you need a new form for each blood test. (Although your doctor can write a standing order for up to a year, maybe I’ll just ask for one of those.)

Oh same here, but I just have a PDF in my email I print out each time.

I see your endo once a year right now. Usually he gives me a requisition when I leave an appointment for the next onw and I have to try not to loose it for a year.

My GP gives me a standing order for an A1C every 3 months and I just get it copied to my endo.

@Scotteric as Jen says they take the form. Now that everything is highly computerized here there seems to be no flexibility. I had a standing order expire by a day and the lady at the lab could not just get me a test because the computer required a new order. Grrrr…

So my bubble of amazing control burst. Hormones kicked in. Several days of crazy highs and lows rollercoastering and not able to figure out what dose of insulin my body wanted. Now I’ve just been running high non-stop for days. I doubled the Lantus dose to 10 units and have been giving many IM injections and running a +50% basal on my pump and am still high. So tonight I will probably take 15 units of Lantus.

I will not get into a rant about hormones. I’ll just say … ugh. So frustrating.

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Update so far: I’ve upped Lantus from five units to 14 units. Seems to have worked fairly well in that highs are MUCH easier to get under control, but I still have to aggressively correct upwards moving trends several times. Decided to increase Lantus to 18 units, but fell asleep last night without taking any. Woke up this morning to find I was flatlined at 18.4 mmol/L (331 mg/dl), so clearly the Lantus is helping. I’ve kept my pump’s basal steady at about 38 units this whole time (including last night). I took my 18 units this morning and will see what happens.

This means my overall Lantus dose is now 32% of my basal dose (started at 12%). I suspect that once hormones end, I’m going to need to use my pump’s temporaroy basal feature quite a bit for a few days of lows, and simultaneously drop the Lantus back down to five units overnight (but I suspect the drop in Lantus may not kick in overnight, which is why I’d rely on my pump’s temporary basal for the first day or so).

Interestingly, I think these sudden huge increases/decreases in basal are illustrating exactly why Tresiba alone did not work for me when I tried it. Not only its flatness throughout the day but also inability to rapidly adjust it by large amounts. Using both Lantus and the pump seem to be helping with both of these issues.


Thank you for sharing. Following w great interest!

I have been using the untethered method for only 5% of my basal on the pump. What a difference it has made. No post prandial hyperglycemia and no hyperglycemia due to disconnecting for a shower :slight_smile:

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