Post-Covid insulin needs

I’m recovering from my first bout of Covid and have noticed my insulin needs have changed drastically.

Normally, I’d need 3-5 units for breakfast, 4-5 for lunch, and 4-5 for dinner. I’d keep most of the day in range (70-180) with a few momentary peaks above and below range. My basal rate was great and came to about 5u a day. My last Hba1c was 5.6% (just before switching to a pump) so I was doing something right.

Now, I wake up and have to immediately set an extended bolus for 6u over an hour. I repeat this until my blood sugar has come down to 100 which can take 2.5 hours. If I eat breakfast within that first hour (about 20-30g carbs), my blood sugar skyrockets to 200-250 and takes even more insulin to bring down. If I wait to eat until it’s 100, I go a little low, need to treat with about 20g carbs, then bounce around 80-100.

The morning extended boluses usually put about 15u in my system. Even though my pump says I have no IOB by lunch, I don’t need to bolus for lunch. Same for dinner, although I can slowly creep up to 150 by the time I go to bed if I don’t correct. But 150 is still a lot lower than I’d expect with no IOB.

My daily usage has gone from 24 units/day to 38 units/day.

The insulin seems to be taking a lot longer to start working.

Is this a common post-Covid blood sugar issue? How long has it lasted for others?

I’ve got an endo appointment next week and I’ll definitely be bringing this up, just wanted to see if I wasn’t alone.


Just like everything else with diabetes, it varies. My own experience with Covid vaccination and infection is that I became very insulin resistant. Vaccination resistance lasted 5-7 days. Actually infection was worse both when positive and for 2-3 weeks after testing negative.

I feel lucky that I had no long term damage from Covid. I did have a short period of exercise induced shortness of breath.


Thanks. I’m sure everyone’s experience is different, but it’s good to know that I’m not alone.

Insulin seems to take sooooo long to start working. And I feel extremely hungry most of the time (that’s unusual for me, so I’m guessing it’s a Covid thing).

This is my first illness since diagnosis, and it’s been a learning curve. The hardest day was peak symptoms where I needed to change my infusion set and my Dexcom. Neither of which is hard or time-consuming, but when combined with an illness are really annoyed ngm luckily, I’ve got a helpful partner and they were recovering as my symptoms were peaking. Oh, and to add to the annoyance, that site only lasted one day as I hadn’t grasped my increased insulin needs by then.

Today has been 100% under 180, so I’m pretty pleased I’ve spotted some patterns and found tactics that help.


Humalog and Novolog have a duration of insulin action around 6 hours. It’s common to set much shorter times in a pump to get more aggressive dosing behavior, so “the pump says 0 iob” has to be taken with a grain of salt. From your description, I’d guess the last insulin from those multiple extended boluses was still active at lunchtime.


Good point. I usually end my final extended bolus around 1pm so still active by lunchtime and maybe still active enough by 7pm when I have dinner.

It does seem like the insulin might be working a bit slower than usual. The amount of insulin I’m doing on those morning extended boluses would have been way too much pre-Covid. Now, they seem to do nothing until hours later.

Hopefully everything gets back to normal in the next few weeks.


Wow. Didn’t even consider my change in insulin requirements were secondary to Covid. I am an RN and never got Covid during the epidemic. In March went on vacation and got a pretty intense case of covid. Still dealing with lung problems. I have been dealing with dawn phenomenal which I never had before. Your post made me consider the covid/diabetes connection. I am on MDI and was even considering going back to a pump which i have been happy without being tethered to a device with tubing. See my Endo next week. Will definitely ask.