Anyone interested in switch from Levemir to Tresiba?

I finally saw an Endo last Friday, and came away with disappointment on the CGM - he hadn’t received anything from Dexcom, though they were supposed to have sent him paperwork - this makes me nervous since I want this done before the end of the year for insurance purposes. I have a call to the Dexcom rep I was given, so hopefully that can be sorted soon.

I also got samples of tresiba and fiasp. I’ve been wanting to try tresiba for more than a year, but had to wait since my GP doesn’t know anything about diabetes and doesn’t have samples and didn’t want to be responsible for starting me on a new insulin, so I had to wait until I saw an endo; something I haven’t done for several years. Anyway, I have tresiba now, and I’m trying it as a basal to replace my current twice a day levemir at 8am and 11:30pm. I’ll leave a log of observations on the switch and how its going in case anyone is interested.


Hi @jag1 I’m sorry about your lackluster endo visit. Call all often! Like, repeatedly call both parties to get this solved before the end of the month.

Also, @Eric might have a suggestion of who at Dexcom to call. I’ve certainly found some reps and some endos to be more useless than others. But the main Dexcom line seems to be working for us now that we got rid of Byram Healthcare. I really CANNOT say enough bad things about Byram. We did not use a CGM for years because of their inability to get them to us. Shockingly awful customer service.

If you have a third party rep, just go around them and try them directly. The support number is 888-738-3646. Try that and see if they can get you elsewhere.


Day1 was Saturday. I had been using a total of 30 units of Levemir, 15 units at about 8am and 15 units at 10:30pm. I had my normal 15 units of Levemir Friday night, then woke up and took 28 units of Tresiba on Saturday. No breakfast (I don’t eat one on weekends) and BG more or less stable till lunch. I ate a well tested lunch (one I eat most days of the year) and took normal bolus. Unlike with Levemir, I found my BG falling repeatedly in the afternoon, requiring repeated small carb intakes. I didn’t count how much, but it was a lot. Especially at around 9 hours after tresiba injection - normally levemir would be starting to tail off at this time, but tresiba seemed to be ramping up. Anyway, conclusion from day 1 is that I am starting with too high a dose of tresiba, So 30 units of levemir does not translate to 28 units of tresiba for me - I need to lower dose more. One nice surprise - I went to bed at BG 102 and woke up with BG 102. I know this is fluke and not a realistic goal, but nevertheless I hope I continue to see good stability overnight with one injection of basal a day. Hopefully this will continue to be true once I get the tresiba better tuned.

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I was surprised. If I don’t hear from her soon I’ll follow up as you suggested. What is a third party rep, and how do I know if that’s what I have?

Day2 was Sunday. I lowered the tresiba amount a bit to 25 units (remember I was at 30 units of levemir for years). Everything good until lunch, but still required unbolused repeated carb intakes during the day - I measured today and needed 15g, 15g, 15g and 25g all before dinner and starting 4-1/2 hours after my lunch bolus, so its not a matter of reducing my bolus amount. Clearly my tresiba is still too high. I’ll try 22 tomorrow. Tomorrow is a normal work-week day (plus aerobic exercise at night), so that may have some impact too.

Glad to see you got some tresiba…

Dexcom customer service has gone downhill horribly since the g6 came out—- they’ve gone from very good to very bad in my experience

I’m sure you’re aware that it might take more than a day for adjustments to settle out…

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It’s likely that the 25 units from Saturday is still active. I understand lowering the dose substantially to 22 units (since it’s better to have too low of a basal than too high), but you may find that you need to increase it somewhere between the two again once you have multiple day’s worth of Tresiba in your system. Though if you weren’t exercising over the weekend, then the exercise Monday night may lower your basal needs even further.

I don’t usually see the full results of a dose change until 3 days afterward.

I’m very interested in reading your thread because I’ve been thinking about switching from Tresiba to Levemir or potentially using both at once. When I’m exercising I need less Tresiba, and despite my best efforts, I haven’t really figured out a good way to deal with the ups and downs of that (in addition to monthly hormone variation). If I could just have a set Tresiba rate of the lowest dose I ever need and then dose with Levemir when I need more, I think that might be the ideal scenario because I get the longevity and consistency that Tresiba provides, but I’ll be more able to address the day to day basal need variation with a little Levemir. Alternatively, I could use Lantus since i believe timing is not influenced by the dose amount as much.

I haven’t decided if it’s worth the effort though. I think I’ll ask my endo when I go in for an appointment this week.

I’m interested in seeing if the lack of flexibility is a problem or not for you.


This is exactly what I experienced - a very strong, prolonged peak about 9 hours after injection. I was able to mostly curb it by lowering my dose, but then it didn’t last even close to 24 hours. Ultimately I returned to pumping or a split dose of Levemir on MDI, but it’s definitely worth trying and seeing if there is a dose that works.


I’ve never particularly noted any stronger action around 9 hours, but I’ve always taken my dose in the evening…

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If you have a dawn phenomenon, for you it could be that the stronger action (if there is any) perfectly matches your increased liver output (if you have that).

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That’s what I was considering… I suppose anything’s possible… I have seen more than a few people in the doc say tresiba seemed to really help with their dawn phenomenon… which could make sense if that’s just the timing of its peak, but I’ve never particularly noted it as being a major issue for me, either dp or a peak in that timeframe

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Day3. I took 22 units today. I woke at 137, after taking a small humalog correction overnight at 4 am (I woke up to pee which happens if my BG is at all high). But that could be either insufficient overnight basal or incorrect food/bolus the night before so not a bad start. I took what would have been a normal humalog correction amount on waking, but went a little low (54) in the late morning, so it looks like I need to lower my waking correction amount when using Tresiba (I saw the same thing the day before so this seems a solid conclusion). I eat a single egg for breakfast every morning and don’t need to bolus when using either Levemir or Tresiba, so this seems consistent.

At lunch started at 70 so took a slightly smaller bolus with lunch; that worked pretty well but 2-1/2 post lunch my BG went down to 63 so I corrected with 14g carb that bumped me up to 130, which then settled down over the next couple hours until I was at 90 at 6 hours post lunch bolus. So BG was trending down in the afternoon, but not dramatically.

Now to throw something new in the Tresiba mix, it was time to exercise, so did my 20min 5K rowing routine 9 hours after tresiba, 6 hours after lunch bolus (no bolus active during exercise). Started at BG 90, then BG immediately after rowing was 70, but then 20 min later by the time I got back to my desk it was 48 so I took another carb correction 21g since I wasn’t going to be able to eat dinner as I normally do immediately after exercise. Later needed another 12g carb correction about 11 hours after tresiba until finally able to eat dinner, by which time my BG was 88.

Using a basal insulin with longstanding T1 diabetes is always a matter of adjustment and compromise unlike using a pump which is infinitely adjustable. So I’ll settle on 22units tresiba for at least a few days as Katers suggested.

So with 22units tresiba in the morning, the day time was pretty manageable. I need to lessen my daytime boluses (for food and correction) somewhat, and it still looks like I have an insulin peak at 9-10 hours after injection. I could adjust to eating an unbolused pre-dinner dessert of a piece of fruit or cookie to meet that peak. More data needed on how exercise will affect this but no major issues there. But so far those adjustments seem manageable.

On the other hand, I had another overnight with a wake up high BG needing correction, more dramatic when taking 22units than it was when taking 25units. So far it looks similar to Scotteric, where dialing down on tresiba amount in order to get a workable daytime basal, leads to insufficient basal overnight. But I don’t have enough data yet to be sure, so will continue to check on that.

Sam, what time do you take your tresiba at night? A large part of the reason that I want to make tresiba work is that I occasionally forget to take my evening Levemir, even though I have a cellphone alarm set for it. It doesn’t happen often, but enough to be annoying. I almost never forget to take a morning basal injection. I think I could get used to taking my tresiba with dinner every night, though I would prefer morning. If I can’t make morning injection work, I will try taking it at night, though. More testing needed.

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You might be ok if you just switch the dose to evening. I think my problem was I had to take a very low dose - 14 units or less - to avoid going low all night, and at that dosage it was not lasting long despite Novo’s claims about Tresiba. It might just work better for some people than it does for others. Maybe there is something about the mechanism of how the insulin forms hexamers or however it works that for some people results in flat, steady insulin release for 24 hours or longer and for others results in a peaky mess. This is pure speculation of course but I definitely think the duration is dose-dependent, just like Levemir.

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In not terribly consistent with timing… I generally take it after dinner and before I start winding down for the night… probably between 8-9 most nights. Based on the patterns you’re describing I think adjusting your time of day you take it might be a worthwhile experiment. I bought and use a timesulin pen-cap for mine that helps me remember if I already took it that day or not if I’m in a brain fog…


Thanks for sharing @jag1

I had an endo appointment in January and was going to ask for a sample of tresiba for fun.

I usually use a pump but sometimes switch to levemir. Before Pump I was on levemir 2x a day like you were doing for many years.

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Day 4. Second day using 22 units of tresiba. BG was high overnight and on waking (173) and used too much bolus as a correction (I know I should take less correction in the morning when using tresiba since I’ve seen that already - just a hard habit to break). Got to lunch at 67, used my normal bolus which covered more carb than I usually eat, but that is easy to handle (add a piece of fruit to my lunch). Stable in the afternoon with a very slight downward trend (117 down to 98 at dinner time). Left work and ate dinner earlier than I had the last couple days, about 10 hours after morning tresiba. This worked great. It looks like days when I can eat that soon after my morning tresiba, I’ll be in good shape and won’t need a snack. On days when dinner is delayed, a small snack around 9/10 hours after tresiba should tide me over. All good.

Best part was overnight. This is the second day at 22 units of tresiba. I had plenty of time to be sure my evening meal was well covered, and went to bed at 110. Woke up at 84. No witching hour interventions needed. Perfect. Morning tresiba once a day may work for me after all.

Now I exercise on alternate days, so this was not an exercise day, but I’ll keep at 22 units and see how it goes on day 5 including evening exercise. Will try to eat dinner relatively early since that certainly helped too.


Settling out for you?

Well if you call Dexcom and they say “you’ll need to contact so-and-so-business-name-here” to get your Dexcom supplies you have one of those third party people involved.

I think calling Dexcom directly might be helpful.

OK, then not a third party rep, but a Dexcom employee. She is being helpful, but I still haven’t received anything from either pharmacy (receiver is DME so coming from a different place). I called her and she will let me know what is going on and whether Joslin has sent the prescriptions to them. Just two weeks left till the end of the year…

Yes, thanks. I’ve been taking vacation time so haven’t been checking in here. I’ve been on 22 units Tresiba for 9 days now. It seemed right when I was at work sitting all day, but I may adjust down a bit (maybe 20?) on days I’m on my feet since I’m seeing downward trends (and need carb bumps) during the afternoon. That will take a bit more fine-tuning.

It is also quite important to get all my evening food properly bolused before going to bed. This has always been true but seems even more so with Tresiba since it has only the previous mornings injection to work with. As long as I do that my following morning BG is in a good range, and I haven’t had any overnight lows at all yet so that is good. The hope of taking basal insulin once a day injected in the morning seems like it really is going to work.

This makes me wonder what happened to the extra insulin I used to take? I went from 30 units of Levemir (in two doses) to 22 units of Tresiba. And my TDD has also reduced by 8 units from about 50 units to about 42 units, so it isn’t that I’ve shifted some of that Levemir basal into bolus insulin. It seems this is common though not universal in some of the reports I’ve seen on the net, indicating it is just more efficient per unit at delivering basal in a lot of us.