Constant lows - Tresiba?

Hey all, my name is John Bodkin and I’ve had type 1 for about 10 years. I recently have had extreme lows and can not figure out why. I recently switched from tresiba u100 for my long acting to tresiba u200. I have now been on the tresiba u200 for only 2 days.

I switched from tresiba u100 to u200 when I switched doctors. We weren’t sure which one I used before as I didn’t know there were different versions. We decided on u200 and I kept my same dosage. 28 units in the morning. Since then I have had constant lows and it’s incredible how low I am staying. I tried 15 grams of carbs wait 15 minutes per usual, and would get as low as 35. I eventually had to increase the sugar I need to the point of needing to drink entire bottles of Fanta. My blood sugar has not gone above 150 despite the harsh amount of sugar and I have not taken any fast acting insulin since I have had these lows.

Everything I’ve read and even my doctor said my dosage should be the same with both versions of tresiba, but that’s hard to believe because of the fact no matter how much I eat or drink (and taking no fast acting) it keeps dropping. In 4 hours my bs has gone down to 40, 4 times, even after drinking and eating close to 300 grams of carbs! This has never happened to me and I want to see if anyone has any knowledge of the different tresiba pens. I only thought it could be the tresiba today (my 2nd day with the u200 tresiba), and my doctors office was closed so I can’t get in contact until tomorrow. I am worried about tonight but have plenty of sugar nearby in case it keeps dropping. If anyone knows about this please let me know! Either way I will be taking half of the tresiba I usually do, just so I can compare and hopefully not have constant lows tomorrow. Nothing in my usual routine has changed besides the tresiba. I sleep at the same time, I eat at the same times, and workout the same amount everyday at the same time.

Hello @Bbodkin welcome to T1n

U200 insulin is twice as strong as U100. For example. If my usual dose of u100 long acting was 30 inputs, the equivalent dose for U200 would be 15 units. Irs not a version, it’s the same medication with a higher strength. You’re taking 2x of your usual dose if you were previously using u100 insulin. Good luck :four_leaf_clover:


Thank you so much for the response. Everything pointed to the tresiba u200. Not sure why everything I read and my doctor said otherwise. Thanks for the warm welcome!

Yep definitely talk to your doctor again. @joe is right. Welcome to the forum!

1 Like

I started out on U40 NPH(?) insulin (I’ve been doing this a while😉), then U80 and my doctor naturally cut the dosage in half - it was logical. When U100 insulin came out he cut it again, proportionately - again logical. Granted it was the same insulin and you have switched - but if your doctor didn’t know or check to see how Tresiba’s dosing compares with your prior formulation (in this case, whether Tresiba is half as strong as what you were taking before), not to mention simple common sense (hmm… maybe we should check that), I would have some concerns about him/her. While the instructions do say Initiate at the same total daily dose of current long or intermediate-acting insulin subcutaneously once a day. I would think that presumes you are using the same strength (in this case U200) of your previous insulin.
Hopefully the adjustment works for you. Welcome to the forum, and I’m looking forward to hearing your contributions!

1 Like

You’ve already received the correct answer ref the u100 vs u200. Not surprising you went low and needed a constant stream of added carbs. I can’t help but wonder about the communication between you and the Endo; highly recommend you relook that perspective. I can’t imagine an Endo advising both types have the same effect; either the comms weren’t clear (at least one of you didn’t understand the other), or office staff didn’t understand and answered on behalf of the Endo (the office needs training), or you need to find a new office/practice.

On the good side, you’re now more knowledgeable and can help others!

1 Like

@Bbodkin Welcome John to the JDRF TypeOneNation Community Forum!

@Joe provided the very definitive and correct answer to solve your “low” issue. Double strength or, Double Concentration of each insulin dose you have administered the last two days.

I very strongly recommend that you read the entire information package included with your insulin - something you should do BEFORE ever using any medication. You should also suggest that your new doctor “read before prescribing” - that is, if you plan a return session with this doctor.

1 Like

I appreciate everyone here immensely. I can’t believe I’ve gone this much time without a support system like this forum. I have known about JDRF for awhile and have donated a few times but never knew about this community.

That’s being said, I have called my doctor and left a message. I spoke with the nurse and basically told her what I had done so they could make a note of it. I had read the tresiba package and the info online and what I took from it was that the doses should be the same. It was very vague. There was even a section on it that described “conversion from u100 to u200” which is extremely misleading. The only way I was able to confirm my thought about the tresiba being more concentrated was through you guys and gals. So thank you guys so much.

Had a pretty bad day today as I went low during a workout (175 to 70 in 25 min). Really bums me out as I’ve been extremely tight for so long and now I am having these issues. I start working out at an elevated BS to account for exercising although I only lift weights with little cardio. Could left over tresiba from the past two days of doubling my dose be the reason for this? I will continue to monitor over the next few days and consider my fast acting dose and food intake with all of this.

Lastly, Im not sure how your various doctors treat you all, but mine seem to be very busy with high traffic of patients, they may be more hands off than others, which is unfortunate. I have no option to switch doctors as I just did because of issues with my old doctor, and it took almost a year to actually get an appointment. I was having my primary care physician prescribe me supplies during that year.


I truly hope that going forward John @Bbodkin that you will not have this hypoglycemic event because of over dosing with the Tresiba. I’d be interested to know the reasoning for the switch from U100 to U200; the change is usually recommended if the required / necessary dose is very large, too many units to permit a single dose with U100.

As for your last question about time with doctor; this morning I had one of my regularly scheduled visits with an Endocrinologist - my primary diabetes care physician. She spent just over 30 minutes of quality time with me discussing changes I have made during the last three months in my management technique and the reasons I made those shifts. We also discussed my thoughts for the future. I’ve lived with diabetes since the mid 1950s. She also provided a brief general physical exam and suggested an additional workout routine for me to try.


Oof I hate the sick feeling that comes along with those quick drops/increases! Yes there could still be Tresiba in your system influencing your bgs. When I take pump breaks I have to be careful for the first day or so after I switch back to my pump because I still have some Lantus in my system that takes about 12/24 hours to clear out, so I’m assuming it’s similar with Tresiba.
It’s not your fault, stuff like this happens from time to time. It’s one of the most frustrating parts of living with diabetes. Hopefully adjusting your doses helps you get back to normal soon!

My endo goes over my blood sugars and basal rates (I’m on a pump) with me, looks for patterns in my BG, suggests tweaks, asks what changes I’ve made on my own, and answers any questions or concerns we have.

1 Like

@Bbodkin we are here to help each other out. The literature in fact may be a bit vague or misleading because it’s exactly the same medication. No worries but long acting can take 2-3 days to settle after a change in dose.

I use an internist. For everything. I see an Endo so I have the correct authorizations, but I rarely need an Endo for support. I also have a retina specialist, that’s one that I can’t live without. I have a kind of a cardiologist, but he’s in the wings not on regular rotation. I do see a dermatologist (a nurse practitioner) that’s pretty much my team lineup.

1 Like

My endo is extremely patient and thorough each time I go in. I never feel rushed and she makes sure to address all issues. It sounds like you got hurried and possibly dangerous advice. From what you shared, I would for sure find another specialist.
Good luck!


I fired 3 doctors in a row because they were all like yours. You don’t have to accept that kind of treatment. I was looking for a doctor that I could text through a medical portal (like MyChart), had a diabetes educator on staff, and who listens to patients’ goals and needs rather than tells them what to do.

I called my local JDRF (twice) and spoke about my wants. The second time I called the person on the phone said, “that sounds like my endocrinologist!” I asked their name and I’ve been with the same doctor now for about 8 years now. – JDRF can’t recommend a doctor, but if you take the time to talk with people who have diabetes in your area about what you are looking for, you will find someone who loves their Endo and is willing to share their information with you. Good luck & don’t settle!


I have been on and off the phone with my nurse relaying info to my Endo (I have to call front desk to receive a call back from my Endo’s nurse, to then get a second call back from doctor!) My Endo is out for the week. Another doctor in his office who works with him called and asked me what my problem was. I explained to him everything that has happened, switching from u100 to u200 tresiba, going violently low and needing constant stream of sugar. I told him I took it upon myself to half the dose I was taking of the u200 from 28 to 14 and that other diabetics agreed with me. He explained to me that I was wrong and the doses are the exact same between the u100 and the u200. I told him there is no way that’s possible because of what my blood sugar was doing and that I am still have problems controlling my blood sugar. I had a relatively good day today with 14 units of u200, floating around 150 BS. He said that is not possible and that “my pen must be broken”. I checked the volume of units left on my pen, and added up my doses from the past week, and it matches up perfectly. The plunger lines up with the exact amount I have been injecting. So my conclusion is that his comment about the pen being broken is wrong. If I thought I was injecting 28 units but was injecting more than that because of a broken pen, wouldn’t there be less insulin remaining in the pen? There isn’t. It’s aligning exactly with all of my nightly doses since I started the pen.

So I guess I’m at a loss for what to do. I was able to get him to prescribe me u100 Tresiba but he refused to prescribe me @ 28 units (where I originally was before all of this and had near perfect blood sugars). He prescribed me for 20 units and said to increase it by 2 everyday if I remain too high BS. Does this all sound as nutty to you all, as it does to me?

I have an appointment with a diabetes center tomorrow to get setup with a pump. Should I bring any of this up to them?

The world has no shortage of idiots @Bbodkin sounds like you need to find a new practice. A pharmacist should have the training to verify what we’ve already said but let me say this: if 14 units keeps you good then 14 units is the right dose. If 56 units keeps you good then 56 units is the right dose. The doctor isn’t supposed to tell you how many units per day, that number is up to you. The prescriber’s ONE JOB is to prescribe enough so you make it to the end of 30 to 90 days and so they should round UP AND ADD 10-20 % more units. If they don’t understand this then run away. Only a poor doctor would behave the way the person on the phone (nurse or doctor) behaved.

There’s no need to talk long acting with a pump trainer because you don’t use long acting in a pump. Only fast/rapid. Your long acting is replaced with a basal program. If prescribed correctly, your copay should be reduced because it’s just 1 kind of insulin going forward with s pump. Good luck :four_leaf_clover:. Nice job staying alive.


Does the practice you go to now actually manage Type1 - are they board certified in it? Not all endo’s do or are - in fact endocrinology covers a number of different areas so not all endo’s handle diabetes. I second @joe 's recommendation that you find a new practice.
Since you’re going for pump training you could ask the trainer to recommend one - even if they’re associated with the current office you have every right to find one that (better) suits your needs. I can’t even imagine how they would advise you on pump management given what they told you before. And no harm in asking the trainer about this doctor’s “advice.” When I started on a pump in my mid-30s I learned some things about diabetes that I didn’t know at the time so you’ll have a chance to ask questions.
A tip - pumps come with different types of infusion sets - there are soft cannulas that go under the skin and they come in a couple of different lengths - that is usually determined by your body type (weight). But the main thing is the insertion angle - the insertion process is different so it’s really a matter of personal preference.
There are also steel needles instead of a soft cannula and some people find them comfortable to wear, despite what they are called…
And lastly there are different lengths of tubing you can choose from, depending on your needs.
Your doctor might write the order so you can mix and match of you like. The most important thing (in my opinion) is finding the one/s you find most comfortable to wear and easy to insert. I find some easier to put in than others but it’s personal percent so hopefly you’ll be able to try some before you start.