How much time in between Lantus and Novolog?

So, I have yet to see my endocrinologist - I’m seeing her tomorrow AM - but I have begun insulin therapy. I’m on Novlog and Lantus. I have been taking my Lantus at 9:30 PM, but tonight I wound up eating late so I took my Novolog at 9. Does anybody know how much time in between Novolog and Lantus is safe? I haven’t taken my Lantus as of yet because I have no idea how long between the two is safe. Any advice is welcome. Thank you!

You need to inject in a different spot (this is important) but you can take the 2, Lantus and novolog, about as fast as you can inject, there is no minimum time. It’s really important to take Lantus at the same time (or times if you split Lantus into 2 doses).

1 Like

@HisWifeTheirMama Lantus is a long term 24 hour insulin. It also is slow to start working in your system. Novolog acts with 5-10 minutes and should be out of your system in 2-3 hours. I often take both at the same time when I need a correction dose of my short term insulin around the time that I am supposed to take my long term insulin. As long as you didn’t give yourself too much Novolog for your meal, you should be fine. I

1 Like

Thank you both. I just now took it. An hour and a half late, but now I know it’s safe to use both together, so I won’t make this mistake again. Thank you!

Crap, now I’m scared - I don’t know what side I gave myself the novolog on and if I did it in the same area, am I going to be okay??

Yeah, I definitely injected in the same side. About 2 inches apart

1 Like

So, being the paranoid mess I am, I did a TelaDoc call and the doctor said I will be fine. Thank God. Never doing that again either. Tonight has been a night of lessons learned! I need to pay more attention to what I’m doing, clearly. I am just so tired tonight so mistakes were made. Thanks to both of you again!

1 Like

We all have these moments when we’re first diagnosed. Mistakes happen. The first year is tough.

You’ve just learned this but when dealing with time zone differences/jet lag , my diabetes educator told me it’s fine if you take your lantus 1 hour ahead/behind to get your shots and body into the new time zone. You want to take your Lantus at the same time as much as possible but if it varies a few times you’ll be just fine.

Good luck with your new endo :slight_smile:

1 Like

Hi @HisWifeTheirMama . As fast as injecting two insulins at the same time, I don’t know about Novolog and Lantus specifically but I was diagnosed in 1963 and started mixing insulins - that is taking two types - after college. In the morning I took one called NPH (a basal insulin) and one called Regular together - no problem. It’s not like mixing drugs and alcohol: the two insulins are different types and complement each other, as it were. You’ll learn about that in your education.
Regarding injecting too closely, you should be fine. The reason for not injecting too closely is to make sure all the insulin stays in your body and doesn’t seep out through the hole for the first injection. But even if it did, it’s not going to flood out like a tidal wave.
You might find it helpful to use a diagram to keep track of where you inject reach type - here’s one I found.


I hope your appointment goes well. Work closely with your nurse educator as you learn. It’s a steep learning curve so try not to get frustrated - you’ll get there!
I highly recommend you check out the book Think Like a Pancreas by Gary Scheiner. He has Type1 diabetes and works in the field so has a unique personal perspective that is particularly helpful. I think you’ll find it a helpful addition to your learnings, Andi found it to be a fun read! Looking forward to seeing you on the forum. Please remember though, if you’re in a panic your first call should be to your doctor’s office/ answering service or your insurance’s nurse helpline - or 911 if it’s an emergency. They can give you the medical advice and assistance you need - we can’t do that here.
PS - I saw in another post that you were having some issues keeping your thoughts straight - is your husband or another family member or friend going with you to your appointment? It might be helpful for both of you.

1 Like

2 inches is fine. When in doubt I’d just use a spot I rarely use (for me backside) sorry I didn’t reply last night. The deal is that you never mix the 2 insulins or Lantus will not be long acting and you’ll overdose. In the early days we could mix our NPH (very poor medium acting) and regular (our fast acting) in 1 syringe, and shoot. You cannot do that with Lantus.

The reason it doesn’t matter is because of the Lantus formula, if you shoot 24 units of Lantus the absorption rate is approximately 1 unit per hour, if you shoot 12 units it’s approximately 1/2 unit per hour. So if you also need a bolus (correction or meal shot) it has nothing to do with the Lantus even if you inject them at the same time (in different spots). Anyway if you ever switch to a pump your basal rate is your Lantus dose divided by 24 as a starting point. :shamrock:

1 Like

Hi Sarah, I’m 51 years T1d & have always been on multiple daily injections. I’ve tried many insulins & in my opinion the best long-acting insulin by far is TRESIBA. It’s superior to Lantus, which for many people (not everyone) does NOT last a full 24 hours, thus requiring 2 injections per day at the same time/s every day. Tresiba lasts 42 hours, which sounds too long but isn’t, as it wears off very slowly. I take it once per day in the morning (any time between 8am-9am (weekdays) and 10am–11am (weekends), with no problems. I also take Humalog (bolus insulin) 2 x per day before breakfast & dinner. I’m a light/low carb eater so that’s enough for me, most people need to bolus 3x per day. Talk to your endo about Tresiba, if it’s not “covered” by your insurance, your endo can put in a medical necessity request for it. Good luck !!
-Joanne

1 Like