Dual Wave Bolus

I’ve been pumping since May of 2002. Four years with the MM508 and three years with the MM515. Both pumps have the dual wave bolus feature, I really never use this feature unless there is a high fat content food that I am going to oink out on (the pizza bolus, etc etc…). A few weeks ago, I read a forum post where a TU member stated her pump educator recommended using the dual wave bolus setting for every meal. Her pump educator called the normal bolus a “skittle” bolus, fast acting sugar bolus. Since all of my meals do not contain “skittles” it only made sense to stretch out the bolus time thus giving myself more units over a longer period of time. After reading the TU forum post, I have began using the dual wave bolus for every meal. My numbers have been excellent the entire time. I have dropped my average on my blood sugar meter 15 points. Anyone else use the dual wave bolus at every meal?

Hey Danny - on my Animas 2020 pump - we have what is called a Combo bolus - you can set it to give you X% of X amount of insulin over a period of time depending on how insulin works in your body. I generally set the amount of insulin I have to give over a period of 1 hour (have experimented as I’m sure you have) - and I find I don’t do spiking of blood sugars like I used to. It all depends on how my BG is at the time - and what I’m eating - and I go from there.

I use this for my main pig trough meals during the day. I used to do the same thing when I was MDI (multiple doseage injecting) as well (pretraining for the pump I guess? ) - giving myself small increments of fast acting insulin as I use/used a pen needle that can inject as small a dose as 1/2 unit.

I’ve used dual wave for parties and such, not every day. I’ve used a square wave in the past, but just got away from the habit. Maybe I’ll start again. Interesting idea.

This is something that I am going to have to look at a little more. This makes perfect sense to me. Think I am going to start playing around with it and see what happens. I am anxious to see if it helps with the spiking that I get. Thanks Danny for the suggestions.

Yes, I use the dual wave every time I eat. It really helps me, especially having
Gastroparesis, and all. With Buffets the dual wave works great. The only time
I use a normal bolus is when making a correction.

I’m really loving this idea…but have struggled a bit with the dual wave before. Maybe I’ve extended it too long…Usually I’ve felt (and been) very high right after the initial bolus and not felt better until the end of the dual wave (which makes sense, I needed that much insulin). I guess my question is: how long are you extending the dual wave on these “normal” meals? Anna mentioned 1 hour…is this what most people use?

And my second question. Danny, you said, “thus giving myself more units over a longer period of time.” How much “more”? I, too, get the spike 1-1.5 hours after bolusing, and am back to normal at 2-2.5 hours. I have been trying to eliminate these spikes, but am worried that since I DO come down at 2-2.5 hours, then if I give more insulin, then I’ll ultimately get low, and if I decrease the initial bolus, I’ll FEEL high during the duration of the dual wave.

I’m EXTREMELY interested as to how this works with you (and other people too!). The concept is very attractive–but I think I need more information/instructions! I’ve only been pumping for 2.5 months and was diagnosed 4 months ago, so any and all explanations are very helpful and will be much appreciated!!!

I wrote about my use of the dual wave/ combo bolus on another forum. I have copied and pasted my post below:

I have been doing something similar for about the last 3 years.

From what I have read in this thread, it sounds like most of you who are using this technique are doing so by calculating a carb bolus based strictly on the carbs in the meal and stretching out some or all of the carb bolus using the square wave/ extended bolus.

I use a bolus calculation technique that is usually referred to as TAG (Total Available Glucose). The premise behind TAG is that a portion of the protein and fat content of the meal will also contribute to carb loading above and beyond the actual carbs in the meal. Whereas 100% of the carbs are accounted for when calculating the bolus, only a percentage of the protein and fats are expected to be eventually converted to glucose. The carb bolus is delivered immediately and the protein and fat bolus is delivered using the square wave/ extended bolus.

I have found through trial and error that for my metabolism, approximately 40% of ingested protein and fats are eventually converted to carbs (my percentages have changed over time as I played with the technique). I total the grams of protein and fat and multiply by 40%. As an example, if the protein and fat total to 80 grams, I would multiply by .40 and come up with 32 grams. With an i:c ratio of 1:10, this 32 grams of protein and fat carb loading would need to be covered by 3.2 units of insulin, in addition to the carbs in the meal. Since proteins and fats are digested more slowly than carbs, the 3.2 units have to be delivered using a square wave/ extended bolus to
prevent a person from dropping too low.

How do I time the square wave/ extended bolus? Again, through much trial and error I find that a delivery rate of approximately 1 - 1.2 units of insulin per hour delivery rate for the square wave/ extended bolus keeps me from dropping too low or spiking too high. So in this example, I would deliver the 3.2 units over a time span of 3 hours (3.2 units per hr/ 3 hrs = delivery rate of 1.06 units per hr, which is within the 1 - 1.2 target delivery rate. The 1 - 1.2 delivery rate is used assuming I was in BG target range to begin with. If my BG is above target, I would use a delivery rate higher than this range or transfer part of the protein/ fat bolus to the carb bolus for immediate delivery. If my BG is below range, I would use a delivery rate which is lower.

As you all have noticed, I also experience a much smaller spike after eating a meal when using this technique. Typically, I see my BG spike as little as 20 - 30 points after eating a pasta meal which will have over 100 grams of carbs. After such meals it is common to see 1 hr post prandials of 100 - 120 and 2 hr post prandials of less than 100. If I delivered the insulin correctly, I will be at or near target several hours after the meal, without ever going low.

TAG is NOT taught or recognized by most medical professionals I have talked with. My TAG percentages are essentially a personalized algorithm for my metabolism of a meal and should not be seen as percentages that anyone else can pick up and run with.

Why does the technique work? Better absorption may be one reason the technique works. My explanation however is that the square wave/ extended bolus on top of a carb bolus simulates secondary phase insulin release, which is how a non-diabetic pancreas would handle a meal. Having once tried Symlin, this technique works better to control my post-meal spikes. However, if you are not sensitive to protein/ fat carb loading, the technique may not work well for you. My understanding is that TAG will work best for someone whose second phase insulin release is less than satisfactory. Unfortunately, most of us are simply given a catch all diagnosis of “diabetes” without any further classification of inadequate first and/ or second phase insulin release.

You can read a lay person’s article about second phase insulin release at the following link:


Thanks Danny,

I should also add that I am a Type 1 diabetic with no endogenous insulin production. This means I have no primary or secondary insulin release and TAG can work well for me.

If someone is a Type 2, they may have adequate secondary phase insulin release, but insufficient primary release. They will spike high after any carb loading, but their body will slowly bring them back into range over several hours using the secondary release. My understanding is in this case the TAG method would supply too much insulin.

I am really trying to understand this well, so I’m sorry if my questions are repetitive, or if I’m not getting something that is clear to others.

I completely understand the concept behind this, but am struggling with applying it to myself, which is self-centered, but maybe Ricardo, you’ll be able to take just a minute to answer my personal question?

I rarely have eaten a meal that goes above 50g of carbs, maybe this is why I’m having trouble understanding? Okay, so my problem isn’t about getting high 2 to 3 or even 4 hours after the meal, its at 1 hour to 1.5 hours after bolusing–while the insulin is supposed to be “working.” At 2 to 2.5 hours I’m usually back to “normal” and worst case scenario, which is very infrequently, it takes until the 3rd hour after bolusing to be completely in target range.

Is there a way to employ the dual wave so that I can avoid the 1 to 1.5 hour spikes? I do understand that it is normal for one’s BG to rise during the hour after bolusing only to come down around 2 hours (right?). I’ve been thinking that maybe I need to try bolusing earlier than I have. Like more like 10-15 minutes before eating, instead of 5.

An additional factor to my difficulty in understanding how to best use the dual wave to help me is maybe because I’m still honeymooning…maybe my body is kicking in with some sort of “secondary phase insulin release” and that’s why I haven’t noticed and post-meal (3-4hrs later) spikes?

I COMPLETELY understand if discussing my personal quandary is not what people are interested in, but perhaps there’s someone out there with an idea for me?? Thank you so much!

Sophie, if you’re back to normal in 2-2 1/2 hours I would just stay
the way you are. You are apparently doing well enough, why change.
If you eat a food with a high fat content and you find yourself high
after 2 hours than you might want to experiment with the dual wave bolus.
Being a new pumper I would leave good enough alone.

Hi Sophie,

I agree with Danny.

Since you are spiking about an hour after the meal, it sounds like the carbs you eat are peaking sooner than your insulin bolus is peaking. If you bolus early as Danny said, it should moderate the spike. However, I would only do this if the meal had more than a minimal amount of carbs and you are expecting a spike. If you ate a high fat meal, the fat will usually delay the carb spike and you may not need to bolus early. With a high fat meal and an early bolus, you may become hypo shortly after ingesting the meal since the effect of the carbs will be delayed due to the fat and your insulin will peak too soon, yet your 2 - 2,5 hour post prandial will be back to normal.

I assume your spikes are more than a non-diabetic’s BG spike of 140 - 160. Also consider that a non-diabetic’s insulin is faster acting than the insulin analogs we take and also it is delivered more directly into the bloodstream. With a pump, you are infusing the insulin into a layer of fat under your skin. Some diabetic’s find that Apidra will act faster than Humalog or Novalog to moderate spikes.

Also take into account the location of your set. Most pumpers may notice that they get better infusion at certain sites. If I have my site in my upper thigh and I go jogging, I can be reasonably sure that I will get faster absorption of the insulin than if I used the abdomen. In this case, I may not need to bolus 30 minutes before eating a high carb meal.

The important thing here is to find out how your body responds and tailor the treatment to your needs. Since you are returning to normal within 2 hours, it does not sound like you need TAG. Instead, it sounds like your spikes can be taken care of through a faster acting analog insulin and/ or pre-bolusing for high carb meals.

Thank you SO MUCH to everyone! All your input is extremely helpful and has given me a lot to experiment with. I am so appreciative. :slight_smile:

After reading this post, I started digging and trying this out. I found this from MM:

The STARTING guidelines that MM gives for squarewave bolus:

50/50 over 30 mins for all normal mixed meals
30/70 to 50/50 over 2-4 hours for high fat foods
30/70 over 30 min to 1 hour for higher fiber foods
75/25 over 30 min for all meals that include correction for high BG

I am not sure how to interpret the last one. I am now two days into doing a dual wave with everything I eat, and I have to say I am not having some problems like I used to with certain foods. I am kind of loving this whole thing. I have been doing 70/30 for most meals, and so far so good. I did one high fat (pizza) the way the above said, but still didn’t have much luck with that. Everything else seems to be working fine. It did really well with pasta, which normally hurts me 4 to 6 hours later. I did a 70/30 over three hours.

These posts were SO helpful!! Thank you.

I love this place! Thanks to each one of you, sincerely. I love learning how to improve what I’m doing. This info is worth “pondering” upon. Great stuff!

I haven’t tried this method, but am intrigued. I’m having a hard time understanding how extending the duration of insulin delivery could help the spike. Aren’t you effectively delaying insulin effect, which in my mind would only contribute to a spike? I would think the only way to avoid the spike would be to deliver the insulin earlier. And perhaps if delivering it earlier and over a period of time, you could then avoid any low from all the insulin hitting at once. Or do I have this all completely backwards?


Great info! Thanks all. I love these kind of experiments (with examples).

I think it’s important to note that a person should be sure basals are steady before playing too much with bolusing. Otherwise, you won’t be able to untangle the results of the bolus and dual wave percentage/duration from the effects of too high or too low basal rates.

I don’t know about you, but I have 10 basal rate changes during the day and it has taken me a long time to get to that point–but it seems to work!

Looking forward to trying the 70/30 over 1 hour for most meals. I was worried I need Symlin, but think the dual wave will help me avoid it. Hooray.

This is really interesting. I’m on the Omnipod though and I don’t think it has that feature.

I think I am going to try this with my evening snack. This is the time of day that is always messy BG wise, no matter what I do! I know my basal and carb ratio is right, I just tested them. But 3 hours after a low fat snack, I climb from 100 to 140-150. I get no spike in the 1-2 hour time frame then a rise at 3 hours. Maybe stretching out the bolus will help with that…gonna give it a try, I am tired of having to correct at midnight. Of course I could just give up the snack but I am not ready for that just yet, hahaha!

I have been using 30/70 over 30 minutes for most meals, and adjusting for higher fat. I never get pizza right, no matter what. I have given up the thought of making it work, and don’t really eat it anymore. This makes me sad because pizza was my friend. LOL! It has been working fairly well. 70/30 for some ice cream worked beautifully with no spikes. Did that over an hour instead of 30 minutes. I so much appreciate this site for turning me on to the dual wave bolus for all meals. It sure has helped my numbers.