Switching Insulin

Hello, everybody!
Until now I’ve been taking Actrapid (rapid insulin) and Insulatard (long-lasting), but my new endo prescribed me Lantus and Humalog. I’m not sure how this will affect me or my BGs, is there something I should know first before doing the switch?
Does somebody else had to go through the same change?

Thank you! :hugs:

Hi @lupiriz, everybody is different for me changing insulin is 1:1 and easy

Test more and be careful to have carbs on you and you’ll be better prepared for the ups and downs of diabetes

Thank you, @joe! I appreciate your help :smiley:

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Hi Lucia @lupiriz, I concur with what @joe says and also suggest that when making the switch that if you are not completely switching on a 1 for 1 basis that you make any changes so that you take a little less insulin until you see how your body reacts.

As an example, adjust carb ratios so that if you take 1 unit of your old insulin for 15 grams of carb [a 1:15 ratio] with your new [Humalog] insulin use a 1:16 ratio. If it turns out you didn’t take enough insulin for your meal, you could probably take a correction later - but wait a full 4 hours before taking additional insulin. I’m not a medical doctor, but this process has worked for me.

Thanks, @Dennis. That is really helpful! I guess I’m afraid of switching because I don’t know how my body will react, but being extra careful seems to be the way to go. Thanks again!


I have to say that I moved to Lantus about six years ago and it made a huge difference for me. Having this as my ‘background’ Insulin has kept my A1c much more regular.

However, it has taken a while to create a ‘sliding scale’ for the Humalog that works for me. It really depends on your daily schedule and work pattern. It’s strong stuff so always keep some carbs with you.

Good luck


Wow, that’s so good to know! Thanks, @nickadoc

I haven’t switched insulin, but have used both Lantus and Humalog since I was diagnosed T1 a little less than a year ago. They are both great. As with all things, you will need to find the right levels for each based on diet and exercise.

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My daughter uses both humalog and lantus. She is newly diagnosed we make changes according to her BS we check frequently. It has worked well for her. Everyone is different. I have no complaints with either.