The difference a brand of insulin makes


Recently I was forced by insurance to switch from Novolog to Humalog. I thought…“well, the pharmacist says they are about the same, so no worries - right?” You decide…

A year ago this time my bg average was 127, average carb count was 112 and standard deviation was 35.9. These numbers are using Novolog.

A year later this time my bg average is 164, average carb count is 120 and standard deviation is 51.2. These numbers are using Humalog.

I have an appointment with my Doctor in two weeks, and I hope to ask if there is even a small chance she could get an over-ride on the insurance rule that I must continue using Humalog. I feel sick thinking of how bad my bg control has deteriorated. :frowning:


This is certainly a good possibility, but may mean an increase in cost.

My insurance has switched between these 2 several times, currently Novolog is preferred. Not sure yet what 2019 will be.

I prefer Novolog, and for me it kicks in a bit sooner, using my pump. But dosage wise I used about the same.

With Humalog, I had to pre bolus more ahead of time, and adjust my basal rate increases to start a bit earlier.

If you can, do more BG testing before and after meals to see if you can better match the Humalog peak action. You might also need higher doses.


I don’t know exactly how much of a difference there is, but one thing that I think is important for almost any medication for almost any condition is to stay with only one so that you can figure out the best dosages. Your average may be higher now with Humalog, but I am going to guess the reason for that is because you have not yet found the best dosages, because they are probably not exactly the same as they were with Novolog. Something that I have often heard many doctors say is that they prefer brand name medications over generic, not because they are necessarily better, but because you know exactly what you are going to get, making it easier to find the best dosage.


I switched from Novolog to Humalog the middle of August of this year, 2018. You’re probably right in saying that I haven’t found the right dose because last year on Novolog my A1C was 6.1% and this year I think it will be closer to 7.3% or higher. I’ve probably been on Novolog for 10 years or more.


Do you set your own dosing ratios or does the doctor do that for you? It normal for those numbers to change over time and even different seasons when more or less active, or vary food/meals.


Best bet get the humalog readjusted. It may take time but it will be worth it. For the doctor to get the insurance to override the Humalog, she/he would have to write why humalog is not effective. The the doc will be asked did he/she try adjusting the dosages. It may be a total nightmare . you can still get the novolog but you will have to pay more. been on both due to insurance


I don’t mean to throw a monkey wrench into the discussion, but I Changed to Fiasp 10 days ago in my 670G and the results so far have been impressive. My 7 day BG average improved to 143 as compared to the 30 day average of 154 when I was on Nonolog for 20 of the 30 days.


I would be scared to ask for Fiasp because the insurance will not pay for Novolog. FIasp is a newer, maybe more expensive insulin if I read the literature correctly.


Did you have to change all of your basal/bolus rates? Did you request the change from your Doctor or did your insurance company suggest it?


Learn to adjust your own basal/bolus rates. They will vary with which insulin you are using. For me, Novolog requires a little less insulin per gram of carb than Humalog, but the opposite is true for others. Test and figure out the ratio yourself. If your doctor wants you to have his approval before you actually change, so be it, but you should be taking the initiative if you truly want to be in good control.

Basal and bolus rates change not just due to type of insulin, but also over time as you might lose more beta cells, plus as a result of change in diet and activity levels, other medications you might be on, etc. You should also be paying attention to how long in advance of meals to bolus for different types of food and under different circumstances. Know how long different foods take to affect the bloodstream for YOU. Takes a lot of careful observation, but these are things that affect your BG and the doctor really can’t help you with much, as people’s digestion differs.

Two good sources of information not only for how to adjust insulin rates, but also a wide variety of other factors to help you get better diabetic control are the two books Using Insulin by John Walsh (or Pumping Insulin if you are a pumper) and Think Like a Pancreas by Gary Scheiner.


Well said, @Uff_Da. I put this issue squarely under the heading of “own your diabetes.” No one has more at stake than the person with diabetes. Diabetes is a dynamic disease. It changes all the time. The sooner you learn how to respond and move with the change, the better your quality of life will be. It does take some study and experimenting but, when mastered, will fill you with pride and a sense of empowerment.

By the way, I think it’s outrageous that the insurance companies can shake up their insulin formularies every year. They have no idea how this swap in “equivalent” medications can wreak havoc in the lives of people with diabetes. Some realities, however, we just have to live with, no matter how unjust. I wish you the best, @Mayumi!


If the insurance will pay for Novolog (which I understand you are saying is the crux of the issue) then I think it is probable that they will pay for Fiasp. There is maybe a 5% increase of cost with Fiasp (as compared to Novolog) - really not much. The larger point is more likely that they both come from Novo Nordisk.

So if the PBM has the contract for insulin with Novo Nordisk then you may have both Novolog and Fiasp available to you (but not Humalog).

If the PBM has the contract with Eli Lilly then you may have Humalog available to you (but neither Novolog nor Fiasp).


I’m sorry if I gave the impression I expect my doctor to make insulin decisions for me. I have been on insulin since 2003 and have used Ultralente, NPH, Humalog, Lantus, Novolog, and Levemir over the ensuing years. I do make all of my basal/bolus decisions and my doctor writes the prescription for whatever the insurance company happens to deem best for me. What I am saying is that I am having more trouble with Humalog than I ever had with Novolog. I care about my diabetes and I do the best I know how to do. I thought by posting here I might get an insight into why I have failed so miserably in the last 5 months on a daily basis, then again maybe not.


I had to switch basal insulin in June due to a formulary change. I was operating nicely on a combination of Tresiba, Humalog, and Trulicity.

Then I switched from Tresiba to Toujeo and chaos ensued. I thought I had a bad Humalog pen so I opened one from a different box/lot and still the same. The new combination didn’t work the same for me even though theoretically it was supposed to.

Ultimately I had to increase the dose of Toujeo 25% to get the fasting numbers down to a more acceptable range and my carb coverage ratio and correction factor for Humalog also changed.

The once a week Trulicity wasn’t keeping the dawn effect at bay for the duration of the week so we switched to the daily Victoza taken to coincide it’s peak effect with the general time my dawn effect strikes. I also have a Dexcom 6 which has been a game changer for me.

Feb 2018 A1C-7.2
Aug 2018 A1C-8.5 :frowning:
Oct 2018 A1C-5.9%


First of all, I don’t think you have failed miserably. If you don’t follow through and succeed in getting access to your favored Novolog, I would suggest this. Re-examine all of your pump settings including insulin duration (many people set this unrealistically low), insulin to carb ratio, all basal rates, and insulin sensitivity factor. I recommend keeping a daily written log of your starting values and any changes as you make them. (You don’t need to do this forever, just long enough until you’re happy with the results.) Try to only adjust one factor at a time so as to make post-change analysis simpler.

All of your pump settings may be close but if they’re all a little off, the cumulative effect will be poor performance.

I think many people, maybe or maybe not you, don’t respect the power of a rational pre-bolus time. The best way to discover optimal times for you is to use a CGM and wait for the downward bend in the blood sugar trace before starting to eat. If you don’t have a CGM, you could simulate this with a series of finger sticks about 10 minutes apart following a meal dose. You won’t have to do this for every meal; you’ll get a sense of an effective pre-bolus time in fairly short order.

I hope some of this helps.


I switched from humalog to fiasp 5 days ago and noticed an immediate improvement: the insulin was absorbed faster and my spikes were lower and my 3-4 hr post-prandial numbers are lower. I have gone from exercising an hour after eating (to lower my spikes despite the humalog) to only exercising if my sugars are a little high after 2 hours (about a 1/3 of the time). The blood sugar lowering effects of fiasp also seem to last longer than humalog. I am very pleased.


@MM1 - Curious you should mention this, as I asked my Endo today whether or not he’d ever seen someone develop insulin resistance to an analog (I’ve used Humalog for as long as it’s been out).

My concern is I now need to pre-bolus 90-120 minutes in advance. Years ago that was 20 minutes. What kind of pre-bolus time do (did) you experience using Humalog?


I’ve been on Novolog for many years now, so fuzzy on the details for Humalog. I also do lower carb now. But best guess is 15-20 minutes Novolog, 20-40 minutes Humalog. I would also take into account if I had “exercise on board”.

Both a big improvement over Regular.