One in four Americans is taking or is interested in GLP-1 drugs like Ozempic for weight loss. This blog explains the Ozempic effect on GI function.

It’s widely understood that GLP-1 drugs diminish your appetite. Here’s something else you should digest: the “Ozempic effect” on GI functionality.

Nearly 12% of all Americans have used injectable GLP-1 drugs such as Ozempic, Wegovy, and Mounjaro for weight loss. An additional 14% are interested. Of these people, an estimated 25% experience gastrointestinal (GI) issues, according to a 2025 report in MedPage Today.

“All of the GLP-1 agonists that we use now cause changes in how everything is secreted in your GI tract,” Dr. Ann Marie Defnet, an obesity medicine and bariatric surgery specialist in New York, told MedPage.

This seemingly small change – GI secretion – can alter your digestion in a number of ways, from your rear to your teeth. Read on to learn whys and hows behind the Ozempic effect on GI.

How Ozempic and Other GLP-1 Drugs Work in the GI

GLP-1 drugs were originally designed to treat people with Type 2 diabetes by regulating blood sugar. In 2014, the Food and Drug Administration approved the first GLP-1 drug for weight loss, Saxenda. In 2017, Ozempic gained FDA approval for weight loss as well, and other drugs followed. Here’s why.

Glucagon-like peptide-1 (GLP-1) drugs are receptor agonists, meaning they cause the molecules in your cells to act in a certain way. Specifically, GLP-1 drugs imitate a hormone, released by your GI tract when you eat, that manages blood sugar levels, sends hunger signals, and slows digestion. For example, these drugs can elevate the insulin released by the pancreas, which moves sugar from your bloodstream to your cells for energy.

Acting like the GLP-1 hormone, Ozempic and other drugs can suppress your appetite, diminish cravings for food and drink, and make you feel full longer.

All of which can launch the Ozempic effect on the GI tract.

Ozempic’s Effect on GI Function: 5 Areas

One mimicked hormone can have a ripple effect, after all. When that hormone is in your gut, the ripple can extend across your GI system. The following are five such GLP-1 side effects on the GI tract.

GLP-1 drugs can cause dehydration. Users of GLP-1 drugs have less of an appetite for food and beverages, increasing the risk of dehydration. Without enough water in the GI system, waste (poop) can become hard, less absorbent, and more challenging to pass, causing constipation and bowel obstructions, including stones.

GLP-1 drugs can excite your colon. The slow nutrient absorption caused by GLP-1 drugs triggers a reflex that stimulates the colon to move food faster, leading to diarrhea. Diarrhea, in turn, makes you dehydrated, which then contributes to constipation. In fact, you might experience both diarrhea and constipation at once, a condition called overflow diarrhea.

GLP-1 drugs slow down your digestive juices. Some research finds people who take GLP-1 drugs are at a slightly higher risk of gallstones and gallbladder infections, owing to the drugs slowing the release of bile (digestive fluid) from the gallbladder into the intestines. For this reason, GLP-1 drugs can contribute to other diseases that trouble the gallbladder and bile ducts. Some studies have found that patients taking Ozempic are at a higher risk of developing pancreatitis, an inflammation of the pancreas triggered by gallstones and the slower movement of bile.

GLP-1 drugs lengthen stomach storage. Because Ozempic and other drugs slow digestion, food sits in your stomach longer. Over a prolonged period, this could lead to gastroparesis, a condition in which the stomach pushes food into the small intestine too slowly. Symptoms include bloating, abdominal pain, and heartburn or gastroesophageal reflux disease (GERD).

GLP-1 drugs could cause vomiting. The food held in our stomach longer due to GLP-1 drugs will add pressure to your gut and stretch its nerves, potentially forcing that food up and out. If you vomit frequently, the stomach acids can irritate the esophagus and lead to GERD, as well as tooth decay, inflamed gums, and foul breath – what some now refer to as “Ozempic teeth.”

How to Limit Ozempic’s Effect on GI Function

Almost all drugs carry the risk of side effects, and wonder drugs such as Ozempic are not excluded. It’s therefore up to patients to be aware and take a little better care of themselves to counter the effects. Here are some recommendations:

• Stay hydrated! Drink more water, even if you have to schedule it. Strive for 11 cups (women) to 15 cups (men) a day. You know you are well hydrated when your urine is light in shade and odorless (get more tips here).
• Know how to feed your symptoms. If you experience diarrhea as a result of taking a GLP-1 drug, cut back on dairy, caffeinated drinks, greasy foods, and anything high in fiber. If you’re sidetracked by constipation, eat more fiber. And in all cases, take smaller portions, eat them slowly, and avoid heavy activity after eating so your body can focus on digesting.
• Take digestion aids. Pepto-Bismol can relieve heartburn and stomach upsets, while probiotics can nourish and help balance your gut microbiome, for easier digestion.
• Keep a toothbrush nearby. If you experience vomiting from taking a GLP-1 drug, have a toothbrush handy so you can wash the stomach acids off your teeth and mouth immediately after.

Lastly, know when to consult a doctor about the Ozempic effect on GI. If you experience severe abdominal pain and/or vomiting, bad diarrhea, an inability to poop or pass gas, or yellowing skin (jaundice), you should contact your doctor.

Learn more about how your gut microbiome works by reading this blog. If you’re considering a GLP-1 drug and want to be prepared for the side effects, request an appointment here.