• Guest - w'd love to know what you think about the forum! Take the 2025 Survey »

“Rapid-acting” insulin taking hours to work…

Hi, I am new on here but been a type 1 for 3 years. I use fiasp and notice I need a lot more come winter and will resume to 1unit to 10g carb come spring. I think after the last 2 years I realise its down to exercise and nothing more. I play golf and walk a lot from spring through autumn then not so much during winter. I tend to eat before exercise and take little to no insulin and then walk the glucose off. After exercise I do get afterburn so watch levels closely for the next few hours.
 
Hi all. I have also been experiencing very weird issues with blood sugar for the last few years now. After switching from Novolog to Fiasp to increase insulin absorption, I have noticed that a lot of the advice on this page is extremely helpful.

If you are experiencing your insulin taking a long time, here's a summary of some tips I have found helpful that work.

1. EXERCISE! If you are not active for at least 30 minutes to an hour every day, it is much less likely that your insulin is going to travel through your body at a high rate. As an audio engineer and producer, I sit at my computer all day. I have noticed that when I exercise (walking is really the most viable option directly after eating to avoid discomfort or nausea), my insulin works much faster.

2. Cut down on carbs. I am a CARB FANATIC!!! Italian food is my favorite. But at this point, I need to cut back to make sure I don't have wild BG. Obviously when you less carbs, your BG is not going to be affected near as much. For example, eggs and turkey bacon for breakfast is great.
I'm not going to act like I eat healthy at all, but it will help your blood sugars normalize.

3. Try a different insulin. Some chemicals that some insulins use may be affecting how your body is absorbing it. It's worth trying different types of insulin to see if this works.

4. If you are stressing about your BG being high, RELAX. Lots of stress can have a direct effect on how your body absorbs insulin and can affect your blood sugar.

5. Try to find a doctor who has dealt with patients who do not absorb insulin well. My doctor has a record of having patients with straight A's, and if it weren't for my body being so weird, I would probably be on that list.

I hope this helps people like your posts helped me.
 
Last edited:
jesusjesusjesus said:
2. Cut down on carbs. I am a CARB FANATIC!!! Italian food is my favorite. But at this point, I need to cut back to make sure I don't have wild BG. Obviously when you less carbs, your BG is not going to be affected near as much.
Click to expand...
I couldn't agree more. When I eat less carb, the ups and downs in my BG are lower and shallower.
 
I was using Novarapid up 'til a few months ago when I switched to Trurapi because the insurance didn't cover Novarapid any more and only the generic version called Trurapi is covered for 'quick-acting' insulin here. I have spikes, sometimes to the mid teens about an hour after I eat, then around the 2 hour mark, my levels come down and continue to decline sharply well after the insulin is supposed to be used up. I got this idea from "Think Like A Pancreas" (I think, may be from somewhere else) - I take the full doze of Trurapi about 15 minutes before eating, then I eat half of the meal and then I finish the meal at the 2 hour mark after eating. Yes, it's inconvenient, but everything about diabetes seems inconvenient, and it is keeping the spikes much lower to around 10.
 
I don't take Trurapi, but I take the same split meal approach with breakfast.

I dose the same amount of Lyumjev every morning and pre-bolus based on how long it takes me to get to down to 5.5 rather than a set amount of time (it usually works out to be 30-60 minutes depending on my starting blood sugar). When I'm around 5.5, I have my first breakfast (bread), then have my second breakfast (fruit) about 2 hours after eating, or when I'm back below 5.5, whichever comes first.

It's not convenient, but I work from home, so it's manageable, and it definitely reduces my breakfast spikes.
 
Hello all,

Just briefly. I’ be been trying Fiasp for the last nine months & I too find that a) Fiasp needs exercising - something gentle & aerobic, not resistance training - to work. And b) that once I am high, Fiasp really won’t bring me down. I have to concentrate on not *getting* high. Once I am, ONLY a walk will bring me down.

Plus c) Fiasp takes much longer to work than the fabled 15 minutes. It’s slightly quicker than Novorapid, but not much. And it’s not the Holy Grail.

I throw it out after 2 weeks because it seems to work even less well then.

Lucy
 
Finnlee said:
I don't take Trurapi, but I take the same split meal approach with breakfast.
Click to expand...
This is a genuine question, I'm not being critical at all but I really want to know about this split dose approach. The reason I'm asking is because I just ate dinner but skipped my dose of NovoRapid completely because I was, pre-dinner, 4.1... too low for my comfort (I'm 4.6 now 30 minutes after eating). But no doctor or nurse has told me I'm allowed to skip or split a dose. I'll monitor closely for the next 2 or so hours. Maybe they haven't suggested it because I haven't asked and it's something I should ask about at my next meeting?

Edit: I should add that the hospital withheld my NovoRapid this morning because I was "too low" but I was so confused I didn't ask if that's something I can, or should, do at home by myself. I don't want a repeat of last night in the 2s
 
LucySW said:
Plus c) Fiasp takes much longer to work than the fabled 15 minutes. It’s slightly quicker than Novorapid, but not much. And it’s not the Holy Grail.
Click to expand...
I have been using Fiasp for a few years now. I find hat the speed at which it starts working is very dependent upon my starting levels.
If my levels are in the 4s, Fiasp will work immediately - so fast that I have to take it after I eat.
As you mentioned, if my levels are high, Fiasp can be incredibly sluggish. Unfortunately, the exercise method does not work with me - exercising with a level higher than 10 puts a strain on my body which means my levels rise. I just have to be patient.
I avoid eating until my levels have fallen below 10 (preferably below 8 but patience is not my virtue).
It is definitely not the Holy Grail but, for me, the Holy Grail is only a complete cure with no drugs.
 

@plantae You quoted a bit of my post where I was talking about splitting my meal, rather than a split dose. They're very different.

I find that at breakfast I'm very insulin resistant. What I've found works for me is to take my full dose of insulin when I get up, eat half my carbs once I'm around 5.5, then eat the other half of my carbs once I'm back below 5.5, or 2 hours after my first round of carbs. Eating everything in one go would give me a big spike, but level off at my target. Splitting my breakfast dampens the spike and I still level off at my target.

This is different that a split dose, an approach some people use for bolusing for high-fat or high-protein meals. That involves taking part of your insulin before eating and the rest later. Fat and protein can delay the absorption of carbs, so they can often cause a initial dip in your blood sugar, then a second wave of increased blood sugar later. Splitting the bolus can help counteract this initial dip and later wave.

It's probably something worth talking to your diabetes team about as it can be a useful tool, but you need to know how to use it and do it cautiously until you know how your body reacts. I'd avoid testing out new bolusing tactics until talking things through with your team. It sounds like you've had a rough time recently with some epic lows and now is not the time to start experimenting.
 
Last edited:
I’ve recently watched a podcast from Dr Jody Stanislaw ( she is a Type 1 practitioner in the US - type 1 from seven years old ) where she talks about the importance of “dose timing” which was fascinating because some of the standard things we are advised on like taking novarapid 15-20min before eating really just doesn’t work for certain foods etc it’s more complex than that and she helped me understand this - I'm about to have a zoom consult with her. Have a look online for Dr Jody Type 1 and see if it might help?
 

Amy, I bet you’re not alone. I found the same with Novirapid - often I left it an hour after injecting before eating. And Fiasp isn’t so different. As I said before, Fiasp just doesn’t get me down from high levels. And then, as with Novorapid, sometimes when I’ve injected more than the usual amount over 24 hrs, sometimes I have a delayed crash which lasts several hours.

I haven’t worked out any answers in my own case. Except, optimally, to use eating & exercise not to get to high levels. In the 5s or 6s, Fiasp generally seems to work. But after the time lag.
 
I've been T1 for 36 years now, diagnosed when I was 10. I changed to Fiasp approx 1 year ago as it was taking 4 hours before my Apidra brought my BG down after eating. For the first few months it was great (along with my libre sensor) but gradually started to take longer to work. Its causing my HBA 1 C to be far too high as it takes so long. Today, my Fiasp has taken 4 hours to start bringing my BG down after breakfast and after dinner, its not usually this bad, not sure whats going on. I changed my sites recently and change my needle every time,not sure what else to do. My DSN just thinks I'm not trying to control my sugars but I am trying so hard. I've asked if I could have a resistance to Fiasp but was told definitely not. Will keep an eye on here in case anyone else has any ideas
 
Hi @Judith 123 if your DSN was capable of doing her job correctly, instead of criticising you, she would look carefully at your Libre records. Then take note of when and how much you’d injected and been able to see in real time the effects of the Fiasp. Fiasp as most who take it are aware, does not react quickly when levels are higher. Perhaps time to insist you saw a consultant.

It is perhaps also a good idea to look at why those numbers are rising high. What are you eating? When are you injecting? The bottom line is though that Fiasp doesn’t work well with corrections. And the DSN needs to educate herself on that.
 
Last edited:
Type 1, 31 years. Currently going through this now. My menstrual cycle affects my sugars ...I have high sugars for 4 days prior and 4 days after. Hormone affecting a artificial hormone I guess. Currently switch to fiasp myself abd also taking ages to drop...sometimes over 1 hour. I will try the fridge hack and I'm going to increase my dose from what I was taking with my old insulin. Also a mother of two
 
Hi @amym06
I’ve been using Fiasp for about 5 years and I’ve discovered that a cartridge of it only works well until about the 150 mark on the pen. I suspect it’s very temperature sensitive.
I also know that if the Basal, in my case Levemir, is prone to decline before the full cartridge is used.
Juggling the two takes lots of dose adjustments and awareness of cartridge use. Some days are better than others.
Then, of course, there’s trying to calculate the best doses, including split doses, for carbohydrate absorption with different foods.
I wish it weren’t so.
I’ve had type one for 53 years but I’m still learning and every day’s different.
Have you read ‘Think like a Pancreas’ by Gary Scheiner?
 
I'm late to the party but I am SOOOOOOO deliriously happy to find you guys! It's not just me who struggles! 30 years of diabetes I am extremely fed up of the lack of routine one can hope for in insulin use. The only way my levels don't go mental is when i don't eat or drink anything. Only eggs, lettuce, cucumber etc doesn't upset my levels. Today i had a couple of biscuits around 9.30, my levels went to 21, i did three injections of around 12 units each time throughout mid morning/early afternoon, went up and down the stairs around 5 times, and only after the third injection at 2.30ishpm did my levels drop, and then dropped massively, going very low. Tool three bottles of lift and 2 savoury biscuits before my levels began to rise. I'll likely go high again now, as well.
 
Unfortunately that's the way it is no logic at all , I just wish there was an up down button to press but it seems mine have probably been wired up wrong .
 

It's very tempting when you don't see any movement after a correction, but for me it takes some time to stop the spike but as soon as the upward curve stops and flattens out, if I've overcorrected it's an absolute freefall.

I usually do 5-10 stair climbs to try and stop the spike a bit, and (as was told) then inject 1 unit for every 3 i'm over 8, so I probably would've gone for an injection of 4-5 maybe? But I know it's reeeal tempting.
 
Last edited:
You must log in or register to reply here.
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn More.…