IBS, gut function and Ozempic

I was at a networking lunch where the lady next to me, after hearing that I specialize in IBS and gut health, started talking to me about her experience on using Ozempic. You’ve heard of Ozempic, right? With the help of this drug, she lost 25 kg (55 lbs) in a year, but as a “side effect” her long term digestive issues were greatly improved. 

Fascinating! I had heard about this in passing before, so I wanted to take a deeper look into the drug and whether this is a proven effect.

But first, what is Ozempic?

Ozempic is a brand name for the drug semaglutide, a prescription medication to help people with type 2 diabetes to better control their blood sugar levels, and more recently to help people lose weight. Blood sugar becomes lowered through the hormone insulin, which is released into the blood stream in larger amounts, and weight loss is becomes possible through lowered appetite. It’s also likely that eating sugary and fatty foods (and drinking alcohol) becomes less rewarding, leading to weight loss. (2) 

Ozempic is a once weekly injection, and it acts as a GLP-1 agonist. This means that the drug mimics the action of the gut hormone GLP-1 (1). And here’s what explains the gut side effects: as a gut hormone it also helps regulate digestion – it decreases stomach movements and secretions, and slows down digestion. 

Interestingly, L-cells that secrete GLP-1 in the gut have different functions depending on their location. In the small intestine, GLP-1 is released in response to nutrients (food) in the GI tract, but further down in the large intestine these cells become stimulated by bile acids, fiber, short chain fatty acids and gut microbes. In the same way, GLP-1 seems to slow things down higher in the intestines and speed things up lower down (5), although some studies suggest that also the large intestine becomes slower. GLP-1 has also been found to improve increased permeability in the large intestine, though the study was done in rats (6).

Ozempic digestive side effects

While the lady I talked to mentioned improvements in her gut issues, interestingly the most common side effects are digestive problems: nausea, constipation, diarrhea, abdominal pain and heartburn. (1) Furthermore, even more severe gut problems can be caused by Ozempic and the like - the risk of pancreatitis, stomach paralysis, bile issues and gut obstruction are increased. It’s not clear why this happens, but it probably has something to do with the ability of GLP-1 agonists to slow down the movements of the digestive tract. (3,6)

When it comes to IBS specifically, some evidence shows that GLP-1 levels are lower in people with constipation predominant IBS and these lower levels are connected also with abdominal pain. However, in a study with mice with something like IBS-C, GLP-1 levels where higher than in normal mice. (4)

Importantly, GLP-1 can worsen stress-related changes in intestinal motility and stimulate the HPA-axis (of which the end products are stress hormones). This is bad news, as stress is recognized as a major trigger of IBS. At the same time, GLP-1 may reduce abdominal pain. (4)

What does this all mean?

This all sounds a bit confusing, so what should you think about this all?

GLP-1 is certainly an important gut hormone that all of us have naturally, but medications that mimic this hormone to boost its function are not unproblematic. And while GLP-1 agonists act on the gastrointestinal tract, scientists are only beginning to explore whether they could be utilized as an IBS therapy at some point in the future. If you are someone who is considering, or already on Ozempic or something like it, please keep the severe gut side effects in mind, so that if your gut function changes drastically, or new symptoms arise, you get them checked out immediately.

Since supportive diet and lifestyle changes are necessary (and based on what the lady told me, often forgotten) even when on this medication, this is a factor to consider and maximize first. If you are not sure what this means, you can write to me.

Also, you can begin supporting your GLP-1 levels naturally by choosing foods that stimulate GLP-1 secretion, like eggs, avocado, olive oil, nuts, and high fiber foods (whole grains, vegetables) (7-12). There’s also some evidence that certain probiotics can enhance GLP-1 secretion, for example Akkermansia municiphila (12).

Get your doc to give you the full story

Many medications have side effects that affect the digestive system. Whether GLP-1 agonists are helpful or harmful depends on the individual. Importantly, talk with your doctor about the GI side effects to make sure the drug is suitable for you. If you are feeling confused, or unsure, ask follow up questions. In fact, any time you are at the doctor’s office and have questions, voice them out! Too often I hear people being disappointed with their doctors leaving them confused about what they should do, especially when it comes to IBS, so demand more detailed explanations. This is your health that we are talking about at the end of the day and it’s the doctors job to explain to you properly.

Thank you so much for reading about this timely topic! Be in touch if you have questions, or if you’d like a topic to be discussed here ([email protected]).

Love,

Anna-Kaisa

PS. Did you download my free ebook yet? Get it here.

PPS. Learn to Meditate –course 2.0 is starting in 3 weeks! If you want a method that gets better at mending your gut-brain axis with time (the root cause of IBS), this course is excellent for you. Sign up here - only $105!

References:

1. Puckey, M. Ozempic. Drugs.com. 2025. https://www.drugs.com/ozempic.html accessed 3/6/2025
2. Smith NK, Hackett TA, Galli A, Flynn CR. GLP-1: Molecular mechanisms and outcomes of a complex signaling system. Neurochem Int. 2019 Sep;128:94-105. doi: 10.1016/j.neuint.2019.04.010. Epub 2019 Apr 17. PMID: 31002893; PMCID: PMC7081944.
3. Dewan, P. Weight Loss Drugs Ozempic and Wegovy Linked to Severe Gut Problems: Study Newsweek. https://www.newsweek.com/weight-loss-drugs-ozempic-wegovy-gut-problems-health-1832375 accessed 3/19/2025
4. O'Malley D. Endocrine regulation of gut function - a role for glucagon-like peptide-1 in the pathophysiology of irritable bowel syndrome. Exp Physiol. 2019 Jan;104(1):3-10. doi: 10.1113/EP087443. Epub 2018 Dec 10. PMID: 30444291.
5. Funayama T, Nozu T, Ishioh M, Igarashi S, Sumi C, Saito T, Toki Y, Hatayama M, Yamamoto M, Shindo M, Tanabe H, Okumura T. Centrally administered GLP-1 analogue improves intestinal barrier function through the brain orexin and the vagal pathway in rats. Brain Res. 2023 Jun 15;1809:148371. doi: 10.1016/j.brainres.2023.148371. Epub 2023 Apr 17. PMID: 37076092.
6. Holst, J. J., Andersen, D. B., & Grunddal, K. V. (2021). Actions of glucagon‐like peptide‐1 receptor ligands in the gut. British Journal of Pharmacology, 179(4), 727-742. https://doi.org/10.1111/bph.15611
7. Santos-Hernández M, Amigo L, Recio I. Induction of CCK and GLP-1 release in enteroendocrine cells by egg white peptides generated during gastrointestinal digestion. Food Chem. 2020 May 30;329:127188. doi: 10.1016/j.foodchem.2020.127188. Epub ahead of print. PMID: 32516710.
8. Bodnaruc AM, Prud'homme D, Blanchet R, Giroux I. Nutritional modulation of endogenous glucagon-like peptide-1 secretion: a review. Nutr Metab (Lond). 2016 Dec 9;13:92. doi: 10.1186/s12986-016-0153-3. PMID: 27990172; PMCID: PMC5148911.
9. Zhu L, Huang Y, Edirisinghe I, Park E, Burton-Freeman B. Using the Avocado to Test the Satiety Effects of a Fat-Fiber Combination in Place of Carbohydrate Energy in a Breakfast Meal in Overweight and Obese Men and Women: A Randomized Clinical Trial. Nutrients. 2019 Apr 26;11(5):952. doi: 10.3390/nu11050952. PMID: 31035472; PMCID: PMC6567160.
10. Hira T, Trakooncharoenvit A, Taguchi H, Hara H. Improvement of Glucose Tolerance by Food Factors Having Glucagon-Like Peptide-1 Releasing Activity. Int J Mol Sci. 2021 Jun 21;22(12):6623. doi: 10.3390/ijms22126623. PMID: 34205659; PMCID: PMC8235588.
11. Indarto D, Rochmah DN, Wiboworini B, Pratama YM, Wibowo YC. Effects of Vegetables Consumption Before Carbohydrates on Blood Glucose and GLP-1 Levels Among Diabetic Patients in Indonesia. Int J Prev Med. 2022 Nov 23;13:144. doi: 10.4103/ijpvm.IJPVM_704_20. PMID: 36618536; PMCID: PMC9811965.
12. Cani PD, Knauf C. A newly identified protein from Akkermansia muciniphila stimulates GLP-1 secretion. Cell Metab. 2021 Jun 1;33(6):1073-1075. doi: 10.1016/j.cmet.2021.05.004. PMID: 34077715.