Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) that affects between 600,000 and 900,000 people in the United States.
In a recent Reddit AMA (Ask Me Anything) hosted by WebMD, Puja V. Khanna, MD, a gastroenterologist specializing in autoimmune and inflammatory diseases at Cedars-Sinai Medical Center, answered users' questions about UC.
"There are a number of clinical trials looking at the effects of GLP-1s in conjunction with traditional medical therapy for IBD," Khanna says.
Glucagon-like peptide-1 (GLP-1) receptor agonists mimic a natural hormone that helps control blood sugar and lower appetite. They are primarily used to treat type 2 diabetes and obesity. Now, scientists are studying whether they could also help lower inflammation caused by diseases like UC.
GLP-1s: A New Option for Treating Ulcerative Colitis?
Ulcerative colitis causes chronic inflammation and ulcers in the lining of the large intestine. Unlike Crohn's disease, which can affect any part of the digestive tract, UC is limited to the colon and rectum.
The most common symptoms of this condition include:
- Diarrhea that doesn't go away, often with blood or pus
- Abdominal pain and cramping
- Rectal bleeding
- Extreme fatigue
- Unintentional weight loss
- An urgent need to go to the bathroom
- Fever
- Delayed growth in children
Although it can occur at any age, it is most frequently diagnosed in young adults between 15 and 30 years old.
Some research suggests that medications that activate the GLP-1 receptor, such as Ozempic and Wegovy, might have anti-inflammatory effects.
Scientists are also studying tirzepatide, sold as Mounjaro and Zepbound, which activates the GIP and GLP-1 receptors. These medications are approved by the FDA to treat conditions like type 2 diabetes and obesity but not UC.
These medications may also promote weight loss by slowing gastric emptying, or how quickly food leaves your stomach. This can make you feel full for longer and lower your appetite, which can help you eat less.
"GLP-1 can reduce inflammation in a variety of ways. One way is that it reduces visceral fat. Furthermore, it also has some microbiome effects and direct effects on some of the inflammatory cells of the immune system," Khanna says.
What the Research Says About GLP-1s
A recent lab study suggests that medications that activate the GLP-1 receptor could help people with UC in different ways, including:
- Reducing substances that cause inflammation
- Blocking bodily processes that increase inflammation
- Helping repair the intestinal lining
- Supporting a healthy balance of gut bacteria
Although the results are promising, GLP-1 medications might not be suitable for some people with UC. They can cause digestive side effects. The most common include:
- Nausea
- Vomiting
- Diarrhea
- Abdominal pain
- Constipation
The evidence supporting the use of GLP-1 medications to treat ulcerative colitis is still limited, and clinical trials are just beginning or are still in the planning phase. The FDA has not approved GLP-1s for this condition, so larger and more diverse studies are needed to understand how safe and effective they are.
Could GLP-1s Make Flare-Ups Worse?
A flare-up occurs when the symptoms of UC reappear after a symptom-free period.
One of the main concerns is whether these medications could trigger or worsen flare-ups. This is a concern because the most common side effects of GLP-1 agonists are related to the digestive system.
For a person already dealing with the chronic symptoms of UC, having nausea or changes in bowel habits can easily be mistaken for a flare-up or the reactivation of the disease.
Some recent studies suggest that GLP-1 agonists may not increase the risk of an intestinal blockage or trigger UC flare-ups as a side effect.
Available Treatments for Ulcerative Colitis
The treatments for ulcerative colitis focus on controlling an overactive immune response. Aminosalicylates (5-ASAs) are usually prescribed for mild cases, while corticosteroids are prescribed for severe flares.
For moderate to severe ulcerative colitis, doctors may prescribe immunomodulators or advanced therapies. These include TNF inhibitors such as infliximab and adalimumab and other biologics such as vedolizumab and ustekinumab.
Newer oral medicines are also available. These include JAK inhibitors such as tofacitinib and upadacitinib and S1P modulators such as ozanimod. In some cases, doctors may recommend surgery.
There is no cure for UC, and flares can return. But a combination of treatment options can help you keep the disease under control and live a full and satisfying life.
"I have had several patients that have achieved long-term remission for decades on a single medication. Infliximab is a good medicine that we have extensive experience with. There have been a number of therapies that have been developed after infliximab that are very good medications as well," Khanna says.
In some cases, the available treatment options are not able to keep UC under control. Some people stop responding to their medications over time, experience severe side effects, or have frequent relapses, so it's important to continue to search for new treatment alternatives.
The Potential of GLP-1s for Ulcerative Colitis
A 2024 study found that people with ulcerative colitis and obesity who took semaglutide or another GLP-1 agonist had fewer complications and hospitalizations. They also had a lower risk of death than those who didn’t take these medicines.
However, this was an observational study, not a randomized clinical trial. More recent research has had mixed results. A 2026 analysis found that adding a GLP-1 agonist to existing IBD treatment didn’t clearly reduce the risk of flares.
Researchers need to conduct more rigorous studies before they can draw firm conclusions about the safety and effectiveness of GLP-1 agonists for people with UC.
"I do see a future where we can prescribe GLP-1s," Khanna says, "but I am not sure if that will be a standalone medication or in conjunction with traditional therapy. I don't think it will be reserved for just metabolic issues, but we have to be careful, as some patients, such as Crohn's disease patients, are underweight due to nutritional issues."
"I hope in 10 years we are able to enter the era of precision medicine to understand why exactly [this condition develops], what will be the best longstanding treatment ... and whether there are ways to cure it," Khanna says.
If you have ulcerative colitis and are considering starting treatment with a GLP-1 receptor agonist, first talk to your doctor and gastroenterologist to weigh the benefits, risks, side effects, and interactions with other medications. Finding the most suitable treatment for UC requires a personalized assessment and the support of healthcare professionals.
Show Sources
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SOURCES:
WebMD/Reddit AMA: "I’m a Gastroenterologist Who Treats Ulcerative Colitis — Ask Me Anything."
Puja V. Khanna, MD, gastroenterologist specializing in autoimmune and inflammatory diseases, Cedars-Sinai Medical Center.
National Library of Medicine: “The alleviating effect and mechanism of GLP-1 on ulcerative colitis,” “Glucagon-like peptide-1 (GLP-1) receptor agonists in inflammatory bowel disease: mechanisms, clinical implications, and therapeutic potential,” “Efficacy of GLP-1 receptor agonists on obesity and metabolic profile in patients with inflammatory bowel disease: a systematic review and meta-analysis,” “Systematic Review: Efficacy, Safety and Metabolic Outcomes of GLP‐1 Receptor Agonists in Inflammatory Bowel Disease.”
National Institute of Diabetes and Digestive and Kidney Diseases: “Ulcerative Colitis,” “Definition & Facts of Ulcerative Colitis.”
My Crohn's and Colitis Team: “Does Ozempic Cause or Worsen Ulcerative Colitis Flares?”
CDC.gov: “Ulcerative Colitis Basics.”
Mayo Clinic: “Ulcerative colitis,” “Diagnosis and testing.”
Crohn's & Colitis Foundation: “What is Ulcerative Colitis?” “Overview of Ulcerative Colitis.”
Medical News Today: “Can Ozempic help with ulcerative colitis?”
