Which one would drop you more? (Lantus vs. Pump Basal)

Hypothetically, if you were using a “perfect” dose of Lantus for basal, vs. if you were using a “perfect” basal profile with Humalog, which one would drop you more during exercise? I.E. Which type of insulin would be more amplified in its effect during activity?


If you leave your basal the same for exercise, any rapid insulin will drop you more with exercise because the physical component to it’s pharmacokinetics rather than the chemical component.

Lantus delivery is slowed down because its pH and the pH of the body, where it slowly unwinds. This is less affected by exercise than the immediate absorption of any rapid, which is greatly increased by exercise (blood vessel dilation, increased blood flow, increased temperature, muscle contraction, etc).

But your question is kind of tricky. You said :

Of course, you can turn off your basal during exercise when using a pump, but not with Lantus.

So if you were to leave your pump alone and start exercising, the rapid would drop you more.

But if you were able to turn your pump off or reduce it before exercise, then the Lantus would drop you more.

Can you share context of the question? Like a scenario?

If the context is unplanned activity where you don’t adjust your pump, then I think the rapid with pump drops you more than the Lantus.

Is that what you were looking for, or did I miss something?


You hit the nail on the head for my question with your entire response, but especially this part.

I was fantasizing about MDI last night after 24 hours on a bum pod site which made yesterday pretty yucky. Couple that with Day 1 of a G5 sensor and data scatter, LOTS of fingersticks yesterday. “Oh stupid new G5, showing a random drop. Lemme fingerstick this…oh sh!t, yup, I’m tanking again.” My basal wasn’t getting absorbed, and I was up’ing my injections for meals and corrections, and I was cleaning all day yesterday which created the Stuck High Then Tank Incredibly Fast followed by being able to catch the tank with remarkably few carbs, and then I’d rebound and be stuck high again until the next tank.

I pulled the pod last night and got things settled down by midnight.

So I was thinking about Lantus vs Humalog for basal and their relative amplification by activity for these reasons.

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Lantus is ideal for this, for a number of reasons.

By itself, Lantus kind of sucks because it has a wacky number of hours for its duration. Like 18 or 20 or 22, some off number that does not line up perfectly with one day.

But with a pump it could work really well, because the off hours would be pump covered.

Here is a quick visual.

Assume in this example that Lantus works 22 hours for you. (You would need to figure out your actual duration, but that is a pretty good estimate to start with.)

Also assume you are taking your Lantus at 8am every morning (I know you would be waking up earlier, this is just an example here).

In this example, the total basal coming from your pod is reduced by about 8.8 units, so that also helps your site last longer. The downside is that you can’t reduce your basal by less than the Lantus coverage amount.

Since the Lantus wears off somewhere in the middle of the night, that is easily picked back up by the pod. So the imperfect Lantus duration ( given as 22 hours in this example) does not end up being a problem.

I picked the idea of you taking your Lantus in the morning, because that way it wears out at night. And I am assuming your nighttime has less activity than your daytime (although I don’t know that would be the case 100% of the time :smiley:).

So just a quick image demonstration of the concept. Just picked some random basal numbers for demo purposes.


  • Redundancy for bad sites or failed pods

  • Less total basal coming from pod helps preserve the site

  • Less impact from temperature, exercise, etc.

  • The Lantus amount could be easily adjusted on any morning to cover changes in your cycle. That possibly seems easier than having to change your PDM basal numbers, right?


  • Have to remember to take your Lantus every morning (actually not a big deal, because if you forget your Lantus injection you could always just do a temp basal to make up for it)

  • Can’t go down to an actual zero basal. The minimum net basal you could do would be whatever your Lantus amount is covering

Okay, your turn! What do you think?!?


Pondering…standby! Thank you for the examples. Those are really helpful!

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Relevant facts:
-135 pounds
-Lantus dose: fluctuated between 11-16 units depending on cycle day
-Always took Lantus at 9:30PM, and then I’d have a crazy drop around 2AM. I didn’t take it in the morning bc then I’d be completely screwed with Dawn Phenomenon and breakfast. And then that would kill the rest of my eating hours trying to get the bottle rocket to come back in a controlled manner.
-My dosing method was to track the number of correction units I took each day, and when I’d need multiple corrections throughout the day, I’d increase my Lantus dose by another unit. I used that whole method (which I came up with myself in the absence of anything better) during my pregnancies. I tried to take enough Lantus to keep my dawn phenomenon/breakfast spike “manageable” (many of y’all would freak out at those numbers) while also keeping my mid-afternoon low and 2AM low manageable.

The beauty of MDI for me was that there were only so many levers to pull. So if one thing wasn’t working, I only had so many options of what else to change. And that simplicity was nice. My A1C’s were lower bc I wasn’t afraid of lows and Lantus lows didn’t feel like bottomless pits…which is how they sometimes seem with pumping Novolog. (I also felt all of my lows back then, in my early days after diagnosis and pre-CGM. I don’t now.) Using Novolog now instead of Humalog, I’m still getting the hang of how it seems to come on strong (for boluses) around the 3 hour mark. I have to watch for those drops and they can be impressive. So this factor makes me conservative on all highs bc as soon as I think I need a correction dose, sometimes it will do a back-flip for me at that 3 hour mark.

*Want to add here, that even though my A1Cs were lower on MDI for the reasons above, my quality of life is WAY higher on my current plan. I’m much more flexible than how I was living on MDI. My life revolved around shots and lows and highs that were always there. It’s not like that anymore, and my A1C is not bad. I’d just like it lower ideally, but only as long as my safety parameters can be adhered to.

Anyway…with that background…I like the idea of redundancy using Lantus to back up my pod site basal. However, I think I’ll psych myself out on problem solving stuck highs bc I’ll never trust if it is a site problem or a Lantus injection leak or my hormones being “fun” that day. All of which would be possibilities every single day. I’m afraid that introducing more variables would in all likelihood edge my A1C even higher with what I’d foresee to be my conservative wait-and-see problem solving approach when trying to find which culprit is the problem.

But I do like examining the possibility of it…mostly due to Lantus not being amplified in its effect the same way that Novolog is. My activity fluctuates so much and so unpredictably that I try to just feed the existing basal. Otherwise I end up causing new problems by turning down my basal too far for too long or not enough anyway…I like things simple. :slight_smile:


Humalog would drop me more, no question. Don’t get me wrong, sustained exercise can still drop me a bit on Lantus. Short periods of exercise don’t seem to cause drops when I only have Lantus in my system.

Yeah, me too :slight_smile:

I know Lantus isn’t for everybody. You can easily change your basal with a pump, and that is a huge plus.

However, there are also a lot of variables with the pump: site degradation over time, site failure, variability in site efficacy based on location, etc.

Lantus is pretty straightforward for me. If I’m trending low at the beginning of the night, I decrease my 9 AM dose the following morning, and if I’m trending low at the end of the night/early morning then I decrease my 4 PM dose the next day. I do the opposite when I’m trending high at those times. These dose times work for my daily basal patterns, but may not work for someone else. This strategy really only works with a cgm because I can easily see the trends with a cgm. If I were just testing, then I’d have to test frequently during the night to understand these patterns - which sounds very unpleasant.

If you’re even a little interested in trying Lantus out again, I’d highly recommend taking 2 doses at different times of the day. They don’t have to be exactly 12 hours apart. Taking 2 doses levels off Lantus’s peak and allows you to be covered (albeit at varying levels) for 24 hours.

I still have to work around Lantus a bit. I chose my dosing times because I tend to need more basal in the evening and less in the early morning. When my basal dose is correct, I generally stay in range in the morning if I have a low carb breakfast. A higher carb breakfast doesn’t work well with the lower basal in my system in the morning, so I would need to dose aggressively and earlier than I normally would at other times of the day.

I don’t think that there is any method of managing diabetes that doesn’t require some work arounds though. I guess it is just a matter of which work arounds fit into your life the best.


How do your combined two doses compare to what you would take if using only one dose of Lantus?

I’m not really sure. When I switched off the pump, I started on Lantus 2x per day. I switched to Tresiba a couple years later and now I’m back on Lantus.

My Lantus dose 1x per day before the pump was higher by several units than my total basal dose after I switched off the pump (2x per day) and my dose now.

However, I was on the pump for several years- probably 7-8 but I’d have to look it up to be sure. My lifestyle was quite different!

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