What affects my blood sugar #52,789,234. Just kidding, but not really. If you thought you already had a laundry list of things that affect your blood sugar I’m going to throw one more at you; ovulation. Ovulation and blood sugar are not the best of friends. Now unless you’re tracking your ovulation you may or may not have noticed this pattern; I certainly didn’t, nor was I ever told about it. It wasn’t until I threw my birth control pills in the trash and started using fertility tracking as my main source of birth control that I noticed the grim reaper of good blood sugar control – otherwise known as ovulation.


How Ovulation and Blood Sugar Mix (hint: not well)

The hormone that triggers ovulation is called the Luteinizing Hormone (LH) – often referred to as the LH Surge because of how fast and strong it comes on. This LH surge tells the body to release an egg and amps up its production of progesterone. Progesterone is important for fertility because it increases libido, improves the lining of the uterus (allowing for better embryo attachment), helps prevent immune rejection of the fetus, and supports new bone formation. But progesterone also has a dark side (at least for type 1 diabetics).

Progesterone is a hormone that, although great for a developing embryo, promotes insulin resistance. Most women see a rise in insulin requirements once this surge starts (usually around day 14-16 of your cycle). If you notice a decrease in your insulin needs around this time it could be a sign of a hormonal imbalance – estrogen dominance.


When Ovulation Strikes…

The resistance can last anywhere from one to two weeks (ending shortly before your period). During this time I personally

  • increase my basal by about 40%
  • lower my insulin to carb ratio from 1:10 to 1:7
  • lower my correction factor from 1:60 to 1:45.

Oy-vey! And the best part… every month it’s a little bit different. Typically when ovulation strikes it takes me 1-2 days to narrow in on the correct ratios for that month’s surge.

When a low carb dish like veggie soup spikes me to 378 (even with a pre-bolus) I know I’ve been struck by the surge!

ovulation blood sugar spike

If you’re currently being struck by the surge and are looking for a good low carb breakfast you need to try my low carb pancakes.


Pinterest Ovulation and Blood Sugar




  1. Leah March 24, 2017 at 4:04 pm - Reply

    AMEN! I have been wondering this for YEARS, and every time I brought it up to my ENDO they would dismiss it. But YES, I run high the second half of the month (which now I know it’s b/c of ovulation thanks to your article). Thank you for this post!

    • T1D Living June 27, 2017 at 4:47 pm - Reply

      Happy to help! 🙂

  2. Jessica Hannan June 25, 2017 at 2:45 pm - Reply

    I’m glad to know I’m not the only one, honestly. I thought I was going batty when I would tell my doctors and would be routinely dismissed. Being brittle is hard enough. It’s even harder when doctors don’t listen to to genuine concerns. I’ve found I also get itchier during my hormonal surges, thanks to my eczema. That symptom is a baseline of knowing what’s wrong with my sugars and wacky body reactions to insulin.

    • T1D Living June 27, 2017 at 4:55 pm - Reply

      It’s so cool when you can read your body’s symptoms. Like, hey I’m itchy and my BG is high…that must mean i’m ovulating. That comes in handy when trying to evaluate a BG reading/pattern. Some doctors are just clueless :-\

    • Savannah October 27, 2019 at 9:07 am - Reply

      Hello I have a question,I actually have looked everywhere online for an answer and still haven’t found out. My daughter is 14 she had Type 1 and she was diagnosed April of this year. Can you have irregular periods because of your sugar,like she has been going on 3 weeks now off and on. But also she’s been active alot more this month due to School and Homecoming…Is this normal or should she see a doctor.

      • T1D Living January 3, 2020 at 1:59 pm - Reply

        hi! yes, it can absolutely cause irregular periods. diabetes is a hormonal disease so it has a big effect on our menstruation if sugars are not in range. If her sugars are in range most of the time then it’s probably not the diabetes doing it. Could be food sensitivity, thyroid issues, etc. <3 and sorry for the super late reply, i took a bit of a hiatus.

  3. Anonymous September 3, 2017 at 11:37 am - Reply

    I knew it. My daughter was diagnosed with type one diabetes when she was just turning 15. As each month came and went I noticed the spikes in her blood sugars around her period. I would tell her.. It’s time for your period. I felt it was a true factor in helping with the anxiety and frustration that came with the high readings. Even though none of her doctors ever mentioned that this could be a cause. As a parent of a diabetic it is always important to take into consideration everything and anything that could affect their daily physical tribulations.

    • T1D Living September 5, 2017 at 1:50 pm - Reply

      I agree, it definitely helps with the frustration when you know the “why”, because then you can plan for it.

  4. Misty October 20, 2017 at 4:18 pm - Reply

    Mind blown. I thought I was going crazy!! I’ve noticed over the years my sugars get heigher just before that time of the month but lately they’ve been really, really high. Thanks for everything! love your blog. Keep them coming!

    • T1D Living October 23, 2017 at 3:23 pm - Reply

      Aw thank you Misty! I’m happy to help <3

  5. shilpa February 16, 2018 at 10:28 am - Reply

    I love what I am reading about everyone so motivated to keep their numbers low. I am so worried about my 18 yrs old daughter who since 9 yrs is still not working towards lowering her numbers. Please let me know if anyone knows how to wake her up. she knows the reality of destructing her organs, she also has pcos, depression ans anxiety she is on lots of medications plus both long and short acting insulin and metformin and have been in the hospital 3 times for having hyperglycemia (ketoacidosis).

    • T1D Living February 20, 2018 at 11:36 am - Reply

      When I was first diagnosed (at age 20) it took me a while to want low numbers. It was hard for me to understand that my numbers today would effect me later on down the road. I think that’s typical for a teen/young adult. It’s hard to see past Friday night, let alone 1 year….5 years… 20 years down the road. Sorry that I can’t offer any more advice, but I bet she will see the value in her health soon. Just keep on keeping on <3

  6. sdfghj June 28, 2018 at 1:06 am - Reply

    Ahhhh thanks for posting!!! Day 19/20 of my cycle (sometimes even more!) it seems to stay at 280-350 no matter what I do … I have tried extended hours of increasing my basal rate by 95%!! They just will NOT budge one bit >:|

    • T1D Living July 10, 2018 at 3:05 pm - Reply

      resistance is a wicked witch! I feel your pain!!

  7. Krystal Montague March 3, 2020 at 12:11 pm - Reply

    Again as others have said, good to know I’m not the only one. My Doc. kept trying to tell me I’m type 1 and 2 now and need to be on metformin. At any rate bacon and eggs will send me skyrocketting, no bread!
    I feel very distracted as I have never had this problem b/f, but now that I’m “perimenopausal” it’s been a major pain.
    Has anyone found something to help with this?
    Hystorectomy is out of the question.

  8. Sarah February 13, 2021 at 12:10 pm - Reply

    Thank you for this! I have been in excellent control and having these out of whack numbers that I can’t reason makes so much sense! I just kept correcting based on BS but increasing my basal makes so much easier. My dr agreed! Trying to fix something that is really out of your control to some point can be frustrating. I have noticed that as I am getting closer to being early menopause the swings have skyrocketed. Having someone that understands is more valuable than you know! I love how the T1D community has grown so strong. We can do this!❤️

    • T1D Living February 24, 2021 at 10:55 am - Reply

      You’re welcome! And I completely agree that staying ahead of the high makes it so much easier to manage than trying to chase it down. Very interesting about the early menopause swings – makes sense because those are some powerful hormones!

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